Sendai is famous for the Tanabata Festival in the summer and in the winter hundreds of trees are decorated with lights. There are things to do, local restaurants, souvenir shops, and hotels.
Sendai is the capital city in the Miyagi Prefecture. This large city in the Tohoku region has many activities all year around. There is excellent local cuisine and attractions.
There are many festivals all year around in Japan. Each festival is different so going to more than one in one location is important. Going to a festival while visiting Japan is a great experience.