Amaama to InazumaSweetness and Lightning; 甘々と稲妻; Amaama to Inazuma

From MangaHelpers: Inudzuka is a teacher who has been caring on his own for his little daughter, Tsumugi, since his wife's death. He's no good at cooking, so they've been eating packaged meals from the convenience store. A series of events lead him one evening to a restaurant run by the mother of one of his students, Kotori. Her mother isn't there, but Kotori does her best to feed them both. It turns out that Kotori is often alone, since her parents are divorced and her mother is frequently not around. The three of them begin to meet and cook tasty food together. [tethysdust]