what are some animes like shakugan no shana?
preferably with cute girls, tsundere elements, interesting story and a flat chested female lead
i gotta say, i never found shana's story compelling at all. Liked the show mind you, but only because of shana.
You should check out ToraDora. Its got everything you noted and a good story to boot. Its romance/comedy rather than action/comedy.
Maybe zero no tsukihime too? it has cute girls, DFC and tsun stuff.
You might enjoy Railgun
Pic related is an MC who is tsundere for another character.