If you're looking for anime similar to Sukui Agete Kurenai ka, you might like these titles.
Eighth grader Yui longs to be a grown-up. She considers armpit hair the symbol of adulthood, so her classmate Takeo—who has the thickest underarm hair in the class—becomes her idol.
Delete Beach is a futuristic tale set in the near future of a schoolgirl who joins an anti-capitalist resistance group. In a society in which carbon-based energy is outlawed but which continues to toil under the regime of expansion and growth, petroleum is the fighters’ refuge. They smoke it, squander it and hand over their bodies to the sea, to eventually provide fuel for future struggles.
It was a season when the tree-leaves turn red. There was a woman crying in front of the child's corpse. She takes the shadow off from her dead son. Just to stay with him she runs with the shadow in her arms through the town at night. Then she makes a promise with a man with darkness...