Akkun to Kanojo

The romantic comedy follows the everyday life of an extremely tsundere (initially aloof and abrasive, but later kind-hearted) boy named Atsuhiro "Akkun" Kagari and his girlfriend Non "Nontan" Katagiri. Akkun's behavior is harsh towards Nontan with verbal abuse and neglect, but he actually is head-over-heels for her and habitually acts like a stalker by tailing her or eavesdropping. Non-tan is oblivious to Akkun's stalker ways, and thinks his actions are cute.

(Source: ANN)