Ai, Sunakawa's sister three years his senior, is shocked to learn during a home visit that Takeo is dating. Having secretly harbored feelings of her own for Takeo, Ai is suspicious of Takeo's girlfriend and launches her own investigation...
When she said she'd fallen for Takeo at first sight, 
you should've known something was off.
Du hättest schon etwas
merken müssen, als sie sagte,
¿No viste que algo no encajaba cuando 
se enamoró de Takeo a primera vista?
¿No viste que algo no encajaba cuando 
se enamoró de Takeo a primera vista?
Dovevi capire che c'era qualcosa di strano dall'istante
Ao dizer ter caído de amores à primeira vista, 
devia ter percebido que havia algo errado.