南月鸫

以及比他小一岁，有一些任性，但是仿佛可爱的妹妹一般的南月鸫(南月つぐみ)。

摘自本作简介中该角色的段落

Another one of Hiroki's childhood friends who is very little sister-like and lives in the same neighborhood. Because of her weak body, her family used to spoil her a little too much and thus, Tsugumi turned into a selfish girl. Like with Risa, Hiroki made another childhood promise with Tsugumi to get married when they're older, but it feels like neither of them want to keep it... She is also the younger sister of Yuuma.

简介来自 VNDB

近所に住んでいるひとつ年下の妹的な幼なじみ。 身体が弱くて家族から甘やかされて育ったので、ちょっぴりワガママで素直になれないトコロがある。 幼い頃に浩紀と交わした結婚の約束があって、自分も浩紀もその約束を守ると思っていたけれど…。

简介来自 Bangumi