lovvlai's manga / #substitute(3)

i guess this is a spinoff or sequel. sagara gets heart broken and his childhood friend who has always loved him becomes the replacement for senpai..

5. two guys who fell in love with one guy during their high school days. however that friend passed away. years later, the two friends have sex in replacement of dead friend who they both liked. --turns out nagisa liked kaito all along.

volume 2 ch. 11. the cool and popular watanabe is liked by all in the office..meanwhile hazuki is jealous of other people's relationship and keep to himself. however,watanabe has interest in hazuki and invites him for dinner. ever since, they would eat together and eventually one day sleep together. while hazuki thinks they are in a relationship, watanabe was just having fun. he was using hazuki as replacement as his first love in high school..but when hazuki found out, he broke it off with watanabe..and of course, watanabe starts to regret. similar to http://www.mangago.me/read-manga/hina_wa_mitsuiro_no_koi_ni_torawareru/