mafuyu's feed

It's a manga, not manwha. It's BL. It has a zombie apocalypse setting, and I distinctly remember the first panel being of a mosquito (which was bitting a zombie) in the bg with the explanation of how the epidemic started. The characters are two high schoolers, they had their uniforms on (or at least I'm pretty sure they did). And one of them gets bitten by the mf mosquito and turns into a zombie, so the other friend uses a single bullet to... End both of them. They did say "I love you" to each other and all. I'm pretty sure I didn't save it cuz it was sad, but I am looking for this because I want to win an argument, and I can't find iiiiit. TT
AH! It may have been an extra chapter from another manga.