Plus-Sized Elf

Plus-Sized Elf (Japanese: エルフさんは痩せられない., Hepburn: Erufu-san wa Yaserarenai., lit. "Elf can't [go] on a diet."), is a Japanese manga series written and illustrated by Synecdoche about an elf girl trying to lose weight. It was originally serialized on Wani Books' Comic Gum website from December 2016 to May 2021, later serialized in Akita Shoten's monthly seinen magazine, Dokodemo Young Champion, since October 2021, and its individual chapters have been collected into seven tankōbon volumes. The manga is licensed for English release in North America by Seven Seas Entertainment.

Chapter 2
Appointment 2: Dark Elf

Having trouble with her magic as her butt has become too big for her power-boosting clothing, Kuroeda seeks Naoe Tomoatsu's advice when he comes to her convenience store one night. Giving her a massage on her calves, it did wonders as her legs feel lighter. As Naoe gives his advice on how to slim down her butt, Kuroeda asks if she will become an ogre by doing this, to which he's not sure. She asks this as she temporarily bulks up.

Appointment 3: Green Scales
Naoe and Erufuda were visiting a fish market to expand her eating habits beyond french fries. There, they meet Mero, where on hearing Erufuda's snide remark on her sagging arms, she laments how they became this way because she hasn't been swimming much since she came to the surface and ate a lot of fish in that time. Naoe points out that this sagging is a result of muscular atrophy in the arms, and she could prevent this by training her biceps and triceps. He also mentions that if she works them out too much, the muscle and fat in her muscles would only make the arms bigger, in which we see an image of Mero in her mermaid form with a heavily-built upper body.

Appointment 19: Muscle Armor (Part 1)
Auntie came from the other world to shape up Erufuda so she can return home, and to do that, she puts her through intense training and makes her eat extremely small portions. However, she comes to the conclusion that Naoe may be the cause of her new lifestyle...