Hida Kizuna possesses the HHG (Heart Hybrid Gear) ability, but it is not strong enough to make him particularly important. His older sister calls him to transfer to a strategic defense school, where many of the students (many of which are large-breasted girls) use their HHG abilities to fight invaders from another world while wearing extremely skimpy pilot outfits. Kizuna's fighting ability doesn't measure up, but his sister has another plan—apparently having erotic experiences with Kizuna will allow the girls to replenish their energy or power-up. It looks like his new school life is going to be full of embarrassment. (Source: MangaHelpers)

When Nasa is called in to work suddenly, Tsukasa faces her first night alone since they married. Struck with loneliness, she takes ahold of the smartphone that Nasa gave her as a gift. Even when apart, they remain connected at the heart.

Yukino Miyazawa is the female representative for her class and the most popular girl among the freshmen at her high school. Good at both academics and sports on top of being elegant and sociable, she has been an object of admiration all her life. However, in reality, she is an incredibly vain person who toils relentlessly to maintain her good grades, athleticism, and graceful appearance. She wants nothing more than to be the center of attention and praise—which is why she cannot stand Soichiro Arima, the male representative for her class and the only person more perfect than her. Since the first day of high school, she has struggled to steal the spotlight from her new rival but to no avail. At last, on the midterm exams, Yukino gets the top score and beats Soichiro. But, to her surprise, he congratulates her on her achievement, leading her to question her deceptive lifestyle. When Soichiro confesses his love to Yukino, she turns him down and gloats about it at home with only a hint of regret. But the very next day, Soichiro visits Yukino house to bring her a CD and sees her uninhibited self in action; now equipped with the truth, he blackmails her into completing his student council duties. Coerced into spending time with Soichiro, Yukino learns that she is not the only one hiding secrets. [Written by MAL Rewrite]

An extension of the summer-arc in the Air TV-series, showing more of what happened during Kanna's, Ryuya's and Uraha's journey to find Kanna's mother.