Name of this manga is Unbalance x Unbalance. It's a korean manga.

faved & sori to hear bout ur fren

looks to me like Tamaki from To Heart 2

if not mistaken, this is the previous Enpatsu no Uchite which died

kos mos is fav character too.like ggxfma said,kos mos doesn't look that good in episode II but not totally bad.she looks beautiful in the cut scenes but not during gameplay.tanks for the wallie