Tonagura!

Tonagura! or Tona-Gura! (となグラ!) is a Japanese comedy/romance story created by Hidetaka Kakei. The manga was serialized by Comic Rush on December 13, 2004, while the anime adaptation was released on July 8, 2006.

Plot
Kazuki Arisaka is excited that her childhood crush and next-door neighbor Yuji Kagura and his family is moving back after being away for ten years. However, her dreams of confessing her love for Yuji are shattered, when Yuji returns as a huge pervert. With the Arisaka and Kagura parents away overseas, both families must learn to live with each other and rekindle the childhood feelings they shared together while attending the same school.

Official
Anime official website