Marui Kanojo to Zannen na Kareshi

Mariko is a lively nurse who doesn't hesitate to make fun of her curves. Nagi is a student who is uncomfortable around curvy people, because of a bad experience when he was a teenager. But when he meets Mariko, he is immediately attracted by her sunny personality. She has no experience of love, and he is very shy. But together they will find true love, beyond appearances and prejudices.
(Source: WEBTOONS, translated)