Aoi Yotaka, the once-legendary assassin known as Nighthawk, is now a lazy, chain-smoking, alcoholic NEET. Sharp-tongued, shameless, and deeply unmotivated, she spends most of her days lounging around her messy apartment with a cigarette in hand. She’s still terrifyingly lethal when forced to act... but good luck getting her to care.

This one is a little different, since it's non weight gain at its base, but you can still make her gain weight if you want😏

Both art and characters belong to Izumida Fuyuki, go check out his manga, Nighthawk Returns