After letting my sister, who's always staying home, try out a dating app... Nagisa Takahoshi AMBI-214

Nagisa, the younger sister, is a homebody and has a severe case of brother complex. Deeply worried about her future, her brother suggests she use a dating app to give her a chance to interact with others. Nagisa decides to meet a man, but unfortunately, he turns out to be the worst kind of jerk, and she is sexually assaulted. Seeing his beloved sister hurt and heartbroken, the brother vows to himself that he will never let her leave again. Thus, to heal their wounded hearts, the two deeply reaffirm their bond and offer each other profound comfort.