The Liar's Long Night -Love Drunk: Continued-(2015)

Usotsukitachi no Nagai Yoru

Chi is an older, unsociable guy who works as a cook at a bar, while Hina is a handsome yet clueless college student who has yet to know true love. Despite his mean looks, Chi is an adorable drunk, and the pair's relationship begins with his drunken kiss.
However, he's still traumatized by a past relationship and has trouble accepting Hina's straightforward affection. Still, Chi can't seem to fall out of love with him, and after the two confess their feelings for each other, they make love for the first time in the staff room.
Meanwhile, Chi's ex returns from overseas to become general manager at the bar he works at. With his sudden appearance, Hina learns about Chi's past lies and mistakes...

(Source: Renta!)