Furueru Te No Saki
Asshole lover (shounen ai so dunno it's seme or uke) x Pitiful lover - dark hair dude has nasty attitude, never treated blond haired guy right. Never let him go beyond kissing, always like of you dun like you can break up. Blonde guy finally start having feelings for a fellow classmate and begins to detach from dark haired guy. Dark haired guy gives surprise visit to blonde guy's house and see him sitting with that fellow classmate.The asshole lover finally realise he actually loves blonde guy he runs out of the place and start crying. Dark haired guy run after him saying that he was prepared to let him go, but seeing him cry made him fall in love with asshole lover again. Happy ending.
Kowagaranai de, Soba ni Ite
If you love someone, let them go. If they don't come back, they were never yours... If they do come back, never let them go.
Aku yori Aku
Story explained: *Incubus/succubus (in this story), if they fall in love they will disappear* Spoiler ahead: Masaki started this story as an incubus. Incubi can't fall in love. When he fell in love with Shimuzu, he lost his position as an incubus and disappeared, but was reborn as a human. (God is generous in this story). When he is turned human, Masaki can't remember his past as an incubus like Shimuzu can as a fallen angel. Shimuzu remembers Masaki, he remembers his love for him, but he also remembers what he did to hurt him. This is why he pushes Masaki away at first. He doesn't want to hurt him again. Masaki misunderstands the rejection, thinking that Shimuzu did it because he misses the "other" Masaki. Shimuzu is also not entirely convinced that this person is his Masaki reborn. He still has love for him and wants to protect him, but he also wants some proof from this Masaki that the two Masaki's are the same soul. Then, Masaki makes it clear that he has no past memories before he met Shimuzu as his neighbor. Only with this proof is Shimuzu convinced that this Masaki and HIS Masaki are one and the same. When Shimuzu takes Masaki in his arms in the final frame, he has accepted that this Masaki is HIS Masaki.
The Specific Heat Capacity of Love
This is my most memorable, heart wrenching manga. The love is real and based on true events. If only animals and birds could talk we wouldn't be treating them so cruelly, probably.
World's End no Niwa