Ugly Duckling's Love Revolution Vol. 2 (manga)

Does being dedicated to a diet really mean the end of fun?! Nope! Whether it’s picking up trash around the school grounds or vigorously participating in an outdoorsy school trip, Hitomi begins to realize that even everyday activities can be part of her regimen. And working up a sweat alongside her buddies is just an added bonus! But there are two sides to every coin, and neither exercising nor her very handsome guy friends are exceptions to that rule! As she puts her body to the test, Hitomi discovers that too much exercise and dieting can be a bad thing…and that one of her seemingly perfect friends might have something of a dark side behind his cheerful exterior…