Slash still seems to hate Ryuuga. He follows him all day, while Ryuuga gets his school teacher job back. Just as Ryuuga is about to teleport back up to his station, Slash confronts him, and they begin fighting. Mahoro busts in and stops them. She lectures them a bit, and then runs off chasing Suguru. The next day, Mahoro is going shopping, and Suguru is supposed to help her, but they end up meeting this small girl, who is being chased by mecha robots out to kill her. She is an android, and they seem to want her dead. So Mahoro protects her.

Since Minawa (#370) is staying with Suguru and Mahoro, they use the pretense that she is Mahoro's younger sister, and that her name is Minawa. She has to attend school with Suguru, since she is supposed to be 14. However at school, she keeps messing up, and getting injured. Meanwhile, at school, Ryuuga and Slash know that she is from the Caretakers organization, so they too keep an eye on her for suspicious activity, since the Caretakers organization is not to be trusted.

Mahoro wants to have a bigger bust, since she was designed as a combat android, her parts were built for maximum efficiency. So, she buys strange machines to try different things. However, they prove to be unsuccessful. The next day, she gets a mysterious package from Vesper, containing a counter-attack device. They are hidden missles in a bra to counter attack a super machine sent by the Caretakers. She uses them, and saves the day.

Mahoro receives word from Vesper headquarters that theres a dangerous item hidden under the school somewhere on the premises. Later reports confirm that it might be a bomb. So, Vesper has Mahoro go and find the item. The Caretakers organization gets word of this, and when the item is found, they try to take it. Meanwhile, the students believe its a magic love-granting item, so they too try to take it. However, it ends up being Shikijou-sensei's time capsule from her student days, and she was trying to find it before the construction workers did.

Its Christmas time, and everyone is planning to have a party at Suguru's house. So, Mahoro and Minawa are doing the decorations. Lately, after school, Suguru has been going up to his room, he is making christmas gifts for everyone in his house. So, they have the party, and everything is fun. They end up trading gifts in Secret Santa Style, and there was mostly junk, but everyone still had a fun time.

Christmas has passed, and now its New Years. So the group goes to the traditional shrine on the first day to get good luck. Of course, there's still the rivalry between Mahoro and Shikijou-sensei, and that persists for the entire course of the winter break. Every day, the group does something different, and each day they have some fun. At the end of the break, everyone realizes what they need to do for the upcoming year, and having had their fun, they have no choice but to get serious again.

There is a famous festival in the city of Hiryu, which stems back from the feudal days. It is a fighting festival, however, due to the rules established in recent years, its rather safe. Anyhow, Suguru wants to participate, and Mahoro is against it. However, he sneaks out, and Mahoro and Minawa go out to find him. However, they get caught up in the festival themsevles, that they forget their goal. In the end, Mahoro ends up winning the festival fighting contest!

Suguru's grandfather decides to come and visit. He actually lives in another city, and is very busy, since he is the Governor. However, he gets worried about Suguru, and comes to visit. While he is there, everyone shows up, and they all have a blast together. Grandfather then realizes that he should not worry, as there are people around to take care of Suguru. He gives Suguru some manly advice, and also has a good talk with Mahoro, after which he leaves. Meanwhile, the Caretakers are planning something...

Since its Valentines day, all the girls are going crazy making and giving chocolates. Mahoro makes some, and meanwhile teaches Minawa how to make some. She then tells Minawa to give it to someone she likes, so she tries Mahoro, then Suguru, but Mahoro stops that. In the afternoon, the girls all stop by and give Suguru some chocolate. However, Minawa takes Mahoro's suggestion to give the chocolate to Hamaji, and she does.

The evil scientist's android comes and tells Minawa what to do, as per their promise. She holds Suguru hostage, and they are taken to their lab. Mahoro finds out from Slash, who gets badly injured in the process. Mahoro pursues them, and Minawa finally realizes the fun she had with everyone. She helps to free Mahoro from the electric holders, but she gets shot in the process. Due to the shocking, Mahoro falls unconscious, and Suguru as escaping, jumps back after her into the the oncoming fire.

Slash's self-repair kicks in, and he goes to get Ryuuga, both of which rescue Suguru, Mahoro, and Minawa. They are then taken to the VESPER base, and Suguru is told the whole story. Meanwhile, Mahoro and Minawa are recovering. They do some tests on Minawa, and her internal systems are kind of messed up, and Ryuuga offers SAINT's technology to fix her. So, she meets up with everyone for a quick trip, and then gets ready to go. Meanwhile, Mahoro has become more and more attached to Suguru, their friends, and her life, and cannot bear the pain to leave anymore.

Events are beginning to happen that will shape the future of the world. The American President was planning to reveal the whole affair to the general public. The Keepers (Caretakers) organization finds about this, and has him assassinated beforehand. Meanwhile, Mahoro fights for her life. For the first time in her life, she is scared of her future, and of death.

Yuuichiro is planning to attend a party held by the Keepers. He was once friends with the leader, but believed that Vesper was the key to the future. However, he goes to the party with the intention of killing them. He prepares a battle plan with Slash. He brings his locket, and as the discussion heats up, Slash is summoned in full battle mode. Slash tears up everyone and everything in the place. However, due to the excess forces of the Keepers, Yuuichiro pays the ultimate price, but the Keepers seem to have been stopped. Meanwhile, Mahoro and Suguru escape to Bolivia. However, they are followed by Feldrance. Suguru is told to run to the nearest city, and Mahoro and Feldrance fight. As Feldrance's strength is continually increasing, Mahoro's is decreasing. So, she is forced to use her ultimate weapon, resulting in a double-KO.

After Mahoro's final departure, the years go by for Suguru. He joins VESPER and becomes an assassin with attributes greater than any android they have ever had. He has one purpose, to hunt down and kill all Androids, especially those affiliated with the Keepers. Although that group is history, there are still some loyal to it, and Suguru disposes of them. One day, after getting quite drunk, he ends up meeting a girl who looks like Mahoro, and it turns out to really be Mahoro, as SAINT's technology, and Matthew's will has recreated her, even though it took 20 years to do so. She finally finds him, and convinces him to finally go back to Tokyo.