Heaven`s Lost Property Forte

Tomoki Sakurai has another dream where the mysterious angel warns him of another Angeloid, and, after revealing the information to his friends, Nymph uses a program called the Dive Game which enables them to revisit the dreams. Tomoki and his friends enter and find themselves in Eishiro Sugata's world, which is an adventure with dinosaurs and rolling boulders, while Mikako Satsukitane's world takes place in a war zone. Sohara Mitsuki is especially embarrassed as her dream world has many ecchi situations with Tomoki. Nymph makes some corrections to ensure they enter Tomoki's dream but instead of finding a grassy hill with an angel, they find themselves in a bizarre world with a tall monolithic column inscribed with illegible words and a hibernating evergreen tree, raising more questions than answers. Sugata goes to the meadow where the cherry blossom is and recalls when Ikaros arrived, associating the giant monolithic column with similar shaped pillars. He witnesses the arrival of a new Angeloid, who seeks Tomoki with deadly intentions.

Finding himself increasingly bothered and aroused by the Angeloids' feminine ways, Tomoki retreats to the mountains to train at a Zen monastery. Sugata warns Sohara, Ikaros and Nymph about the new threat to Tomoki, but the two Angeloids are not concerned about the Delta-Class Angeloid Astraea, who has a lack of computational abilities, which proves true as she immediately bungles her attacks. Later, as Tomoki buries his dirty magazines, the Angeloids interrupt him with different schemes: Nymph, who is irritated by his lechery and dislike for small chests, uses a device to enhance her age; Ikaros incinerates his magazines; and Astraea transforms into a dirty magazine. Later, Astraea serves Tomoki his meal but forgets to poison it. In the ensuing fight, Tomoki, remembering his grandfather Tomozo's perverted advice, puts Astraea through his lecherous version of the Six Domains. After Tomoki returns, Ikaros surprises him by restoring his dirty magazines, which then celebrate with a parade. Meanwhile, Astarea falls into Sugata's campsite. As she reboots, she unintentionally reveals her mission in front of Sugata.

After unexpectedly divulging secret information, Astraea attacks Sugata but is easily captured. Mikako offers to help train her against Tomoki. The gang participates in another festival at the Satsukitane shrine, but the theme this year is professional wrestling. With a ten million yen prize, Tomoki debuts as Mask DuPants, much to the guys' cheers and the girls' jeers. Using ecchi wrestling holds and finishing moves, DuPants advances easily through the tournament, and battles the Angeloids in a tag team elimination match. The finals pit DuPants against Mikako in an electrified steel cage match. DuPants gets the advantage until another masked wrestler, implied to be Sohara, interferes and delivers a devastating backbreaker on DuPants, who stands but it is announced that he is already dead. Afterwards, Mikako awards the prize to Tomoki, but he must fight for the World Title against Judas, who was the shooting range man from the previous year. The closing credits show other early round matches involving the townsfolk and teachers.

Winter comes to the city, and Astraea is still far from completing her mission of eliminating Tomoki. Mikako reels her into another of her sadistic schemes, staging a snowball battle between the girls and boys of her school, with the rule that you can still battle if you get hit and until the commander, Mikako versus Tomoki, loses. The winners get to boss around the losers for a day. While Mikako steps aside, taking Ikaros and Nymph, to search for a hot springs, Tomoki and the boys stage an assault on the strongest girl on the team, which is not Astraea but Sohara. At dusk, while the surviving girls relax at the hot springs, the boys appear to have the advantage, until the popular boys rebel by freeing the captured girls, and Tomoki's team must face the wrath of the "Abominable Snow-hara Man". When Tomoki get stuck in the snow, Astraea has her chance to take out Tomoki, but Ikaros arrives to prevent that from happening. The next day, Sugata comments how Astraea is not allowed to return to Synapse until she kills Tomoki, something he pities on her about.

Sugata and Sohara use Nymph's Dive Game program to travel to Tomoki's dream world, which is revealed to be Synapse, a bunch of floating islands hovering above Sorami. Sohara accidentally tips an object, which rolls and falls to the world below. The two then walk through an Angeloid village to a dome where Sugata enters a portal and finds himself observing activities in Sorami. He then finds himself in a room full of encapsulated humans, with Angeloids monitoring, and he questions his humanity. He encounters the Harpies, who have a hold of Sohara, but since he has the Dive Game on a time limit, Sugata and Sohara return to their world safe and sound. At night, Tomoki takes the strange object and builds it into a transforming panty robot pedal bicycle. He uses it for his lecherous activities and treats it like a brother, that is until Sohara discovers and destroys his friend.

Astraea enrolls in Tomoki's class, but has to stay for remedial lessons, due to her lack of comprehension. After informing Tomoki that he is the least popular boy in school, Mikako holds a game show to settle the situation. With Sugata hosting and Ikaros supplying the questions,[note 15] only Nymph does well. The others suffer penalties from ecchi ravishings to cesspools and peltings of trash. However, when the questions shift to ecchi school girl trivia such as Sohara's measurements and other girls' panty colors, Tomoki catches up to Nymph. The final question, a freebie repeat of an earlier question about the ethics of an open door to the girls' locker room, causes Tomoki to struggle between choosing the correct answer and being a man. Later, Astraea challenges Tomoki in a dummy rematch, but ends up bonding with him from the games, and feels accepted at their barbecue. Meanwhile, Daedalus, the angel in Tomoki's dream, watches over her Angeloid daughters, until she is attacked by the Harpies and the Master of Synapse, who informs her he is deploying his new generation Angeloid.

Tomoki has a dream where Daedalus warns him of another Angeloid, who then interrupts the communication and chokes Ikaros. While Ikaros shops for groceries, an impoverished Astraea and Nymph raid Ikaros's watermelon patch; when she returns they try to regrow the patch but transform it into Venus flytrap looking melon monsters. After Astraea makes fun of Nymph's lack of wings, Nymph ponders how useless she is without a master. Sugata asks her to set up the Dive Game portal for some quick visits to Synapse, but during one of the trips, Nymph is pulled away for a date by Tomoki, leaving Sugata about to be attacked by the Harpies, until Daedalus pulls him out. Ikaros sees Tomoki and Nymph walking, and feels some emotions in her chest. Tomoki tells Nymph he wants to become her master, but before she starts the imprinting process, Tomoki tells Nymph to blow herself up. Nymph realizes that is not Tomoki, who then reveals itself to be the second generation Angeloid, an Epsilon-Class named Chaos, who chokes Nymph while questioning what is love.

Chaos causes Nymph to have multiple hallucinations of Tomoki abusing her constantly.While flying Ikaros sees Tomoki with Sohara and goes to search for Nymph. Ikaros arrives to assist Nymph against Chaos. Daedalus reveals to Sugata that she is the creator of the first generation Angeloids, different from Chaos. Ikaros is manipulated by one of the hallucinations, ordering her to kill Nymph, but instead she tosses her far away from danger. Nymph finds Astraea and tells her to help Ikaros, but the Master orders her to destroy Nymph. Just as she is about to carry out her order, Tomoki stops her and asks whether she will do the bidding of the Master or find the strength to choose her own destiny. When the Master orders her to kill Ikaros instead, she flies to the scene, but she breaks the chains and faces Chaos to a death match. Although Chaos still has the upper hand, Ikaros arrives and fights Chaos unassisted, eventually plunging Chaos to the depths of the sea, leaving her being asked what is love. Astrea then managed to recover Ikaros with both of them pondering on what is actually love.

For this year's festival at the Satsukitane shrine, Mikako holds a "yo-yo" fishing contest where all the girls are tied up in a pool, and the guys tied on ropes must grab them out of the water. The winner is whoever can catch the fish with the biggest "yo-yos". Tomoki transforms into Tomoko for this competition, teaming up with Sugata, while Mikako partners up with Judas. Tomoko manages to snatch some of the girls until Sugata baits the buxom Astraea with some snacks, but Mikako steals the catch. Sugata then brings up the "legendary fish", one whose measurements are still growing. Tomoko transforms back to Tomoki and finds the legendary fish only to be knocked out by her karate chop. Ikaros receives a farewell letter where Tomoki proposes to her. Tomoki clarifies by giving Ikaros and Nymph an allowance. After hearing from friends on different gift suggestions for Tomoki, Ikaros decides to follow Sugata's advice, and buys herself a watermelon, after which Tomoki affirms she did good.

Tomoki seeks some alone time from the girls, first in the bathroom until he is washed out, and then in a closet where he is almost cooked and then washed out again. On a shopping trip with Sohara, Ikaros notices a bridal magazine and asks her about Tomoki's proposal. Later, Tomoki hides in his room and puts the final touches on his "summer project", a massive network of periscopes which allows him to peek at girls all over town. Astraea and Nymph each visit but Tomoki chases them out. Sohara visits as well, but instead of giving him a karate chop, she asks why he still peeps despite having beautiful Angeloids in his house, putting him deep in thought. After Sohara leaves, Tomoki loudly remarks how stupid Sohara was for not noticing his network. The girls get revenge by pretending to strip outside. When Tomoki peeps, the girls aim mirrors to blind him with sunlight. Tomoki retaliates by showing his "unit", shocking the girls. However, when Ikaros takes a look, Tomoki is making a kissing gesture, flushing Ikaros with emotion. She overheats, and decides to repair herself by erasing all memories of him. Meanwhile, Chaos, having interpreted love as inflicting pain on animals, emerges from the sea.

With Ikaros feeling ill, Tomoki and Sohara go to school where Sugata and Mikako are watching a typhoon soon approaching. Later, Astraea investigates a twister, but is attacked by Chaos, while Ikaros continues to struggle with losing her memories. Tomoki goes through the Dive Game portal to meet Daedalus, who gives him a special lock, while Nymph and Ikaros join Astraea against Chaos, who easily subdues them despite their coordinated attack. Tomoki returns and tells the Angeloids to live and that he will be the master for Nymph and Astraea. The Angeloids manage to free themselves and are revitalized by his love. Nymph generates new wings and uses a hacking field to boost Ikaros and Astraea's combat powers. After Ikaros launches her attacks, Astraea does one final lunge, knocking Chaos to the ground. Despite Chaos's pleading to be "loved to death", Tomoki arrives and pets her head, and Chaos starts to experience feelings of genuine love. Tomoki then puts Daedalus's lock on the collar chain of Chaos.

Tomoki and Sugata return Chaos to Daedalus. Things return to normal, with Nymph restoring Ikaros's memories, and Tomoko later teaches Ikaros bathroom etiquette. However, Tomoki has one more perverted task, which is to transform into pool water so he can fondle girls during swim class. After Sohara and Nymph drain the pool, Mikako decides he needs to be taught a lesson. Tomoko escapes the hunt by hiding in the girls' bathroom, but is eventually trapped. While Sohara saws down the door lock, Tomoko has no choice but to escape into the toilet and go through sewage treatment to the sea. Later on, Ikaros, in trying to practice bathroom etiquette of knocking and flushing, knocks a hole in the door and flushes Tomoki again. As Ikaros searches for Tomoki, Mikako sees her and offers to help with her proposal situation. A flushed out Tomoki is taken to a wedding chapel. With Sugata and Mikako presiding, Ikaros appears dressed in a bridal gown. She and Tomoki go through a wedding ceremony, but when they are about to kiss, Tomoki stops. Mikako then gives him a choice: he can pick Ikaros, Nymph, Astraea, or Sohara, all of whom are dressed as brides. Tomoki screams at the indecision, but the ceremony is interrupted by a reformed Chaos, who gives Tomoki a hug, and becomes the newest resident Angeloid.