Responses
They weren't in a relationship. Hayashida was in a relationship with someone else called Yumi. That's who is smiling in the picture with him. You can find their story in Azami and Sabita Yoru.
http://www.mangago.zone/read-manga/azami/
http://www.mangago.zone/read-manga/sabita_yoru_demo_koi_wa_sasayaku/
Ah so I was not crazy. But I never connected any of these. Thank you! ヾ(❀╹◡╹)ﾉ~
Only now have I realized that Hayashida and Natsuo were in a relationship with each other before their current partners in their stories...