Looking for a specific manga

[ryousekki]

the synopsis I remember about this manga is
-protagonist got a crush to the main heroine still cant confessed
-someone from the future came tell the protagonist he needed to mate to the main heroine to prevent some big catastrophe
that all i scan remember about this manga forgot the name if anyone knows the name of the manga please tell me

 

[nihonbashi]

I remember reading something like that in the past... DNA² maybe??

 

[Aquahorse]

the synopsis I remember about this manga is
-protagonist got a crush to the main heroine still cant confessed
-someone from the future came tell the protagonist he needed to mate to the main heroine to prevent some big catastrophe
that all i scan remember about this manga forgot the name if anyone knows the name of the manga please tell me

Yeah, I think it is DNA². Anime is great, although I didn't read manga.

 

[ryousekki]

already find what im looking for after long search gonna try that DNA also

thanks for the answer