It’s been three years since Nishi High’s Hiromi Oka was taken under the wing of former tennis superstar and “demon” coach, Jin Munakata. Fresh off a national championship win, Hiromi has been selected to represent Japan in New York for an international tournament. Unfortunately, Munakata is suddenly hospitalized after his own demons finally catch up with him. Forced to continue on without him, Hiromi must find it in herself to keep playing in the face of new challengers and heartbreaking tragedy. (Source: Discotek Media)

Two years after meeting Aoi, Kaoru and gang are still up to their normal habits. Kaoru now in grad school and the tenants being as rowdy as ever what will become of Aoi and Kaoru's love. Two years has passed since Aoi and Kaoru were freed from the bonds of their families. They continue to live their normal lives with their usual friends in their house.

Kaoru Hanabishi, a college student who lives alone, met a beautiful but bewildered girl dressed in a kimono at a train station. He volunteered to guide her way to the address she was looking for, which happened to be in his neighborhood, but turned out to be an empty lot. Not knowing what to do next, Kaoru invited the devastated girl to his apartment and asked for any additional clues to her destination. She supplied him with a photo of two children whom Kaoru immediately identified as himself and Aoi Sakuraba, his childhood friend. It turned out that the girl in front of him is Aoi Sakuraba herself, his betrothed fiancee who came all the way to Tokyo to marry him. Her revelation was not only surprising but also reminded the deepest part of Kaoru's memory for why he left the Hanabishi family in the first place.

It's sometime in the future and the story starts off with Kei and Ai running for their lives. Ai is a little girl who holds a terrible secret which could destroy the current world. The world is now populated by Headmeters, people who have psychic powers and their strength is shown on their forehead when they fight. However, Kei was an experimental subject and his strength never went above level 5 while other surpasses his ability effortlessly. While escaping, when in desperate moments, Kei could increase his ability to infinity when Ai is in trouble. The one who's after her have a deep secret, aided by a small dwarflike man living in a robotic suit. Eventually Ai is captured and Kei, a sherlock holmes detective and another Headmeter who was converted to the good side when Kei unleashed his horrible powers through Ai must go and rescue her. Together they must save Ai and the secret which she holds. What is the secret of Ai? Who is she? (Source: AniDB)