If I'm not wrong this one's connected to A Sigh In Spring, A Love In Summer, its called Yurameku Aki no Koi Gokoro (Yaoi). Since the main characters in this manga appear in it.
There's an other manga that's also connected to thw two mangas i mentioned in my other comment but idk which one is the third one its been a while since I read these Mangas.
I bet it's the Hinekure Sakura one
HAHAHA idkk maybeee ╮(￣▽￣)╭
Can someone please tell me the other stories that are connected to this one!!!