TIME DRIVER: Bokura ga Kaita Mirai

Yuuto Matsubara is a 27-year-old man who works in the sales department of a major toy maker, but he isn't able to pursue his dreams, and he feels hollow every day. He's even given up on love with his childhood sweetheart Ai. One day a "Time Driver" robot that runs on the power of dreams appears in front of him, and he is forced into the cockpit against his will. Inside is a 12-year-old version of himself.

(Source: Anime News Network)