1) Don't even think about it.

2) Don't fall in love with them either.

These are rules that you should follow if you decide to remain friends with your ex. Do those rules apply to your brother’s ex as well?

Tzuyu finds herself trapped between family and a girl who has the word "trouble" written all over her, Minatosaki Sana. Tzuyu has heard many things about Sana from her brother... about how she cheated on him. With limited resources, can she be so quick to judge that she doesn't give Sana a chance to prove her wrong?