Ep. 5: Kazuki faces romantic chaos as Mitsuki deals with D and Yayoi moving in.

5

Kazuki attends school while pretending to be Mitsuki Sanada's younger brother. Male students deliver love letters for Mitsuki and attempt to purchase the lunch she prepared for him. Annoyed that Kazuki accepted these letters, Mitsuki forces him to write individual responses. The following day, Mitsuki learns that D is moving in with them. Ken Sanada assigned D to Kazuki's room to improve pilot morale, noting that D responds to Kazuki. Consequently, Mitsuki constructs a wall to separate them. The group handles household chores, but Mitsuki becomes upset when D follows Kazuki's instructions rather than hers. She grows angry when D accidentally discards her diary, though she claims it does not matter. D searches for the diary in the rain while Mitsuki and Kazuki look for her. Upon returning home, Kazuki discovers an additional door in his room. Mitsuki enters, and they realize Yayoi, who lives next door, will now be part of their daily routine.