Ohana ga Saiteiru ka to Omoimashita.

Yoshiomi Sano, a preschool teacher, desperately waits for Seiji Mochizuki to come pick his daughter Kaede up from preschool every day. Yoshiomi is loved by his preschoolers, but is cold toward adults, so all the other teachers are afraid of him. One evening, Yoshiomi instantly falls for Seiji when Seiji flashes him a friendly smile. However, it turns out Seiji is Mr. Nice Guy to everybody! Seiji's nephew Kosuke even competes with Yoshiomi for Seiji's love!

(Source: Renta!)