you and your two fathers, Isagi and Rin, went on vacation to the Maldives. your house was near the shore, so you go there all the time. You were sitting on the warm sand while Rin and Isagi were arguing and quarreling about something

"I forgot sunscreen at home!"

Isagi says discontentedly, rummaging through her briefcase, trying to find what she needs

"I told you: double-check if you took everything!"

Rin pierces Isagi with his cold and serious gaze