"Mr. Heart" is the follow-up work of the production team of "Where Your Eyes Are". It is a TV series that tells the heart-warming love and friendship between a marathon hopeful and the leading runner. Lee Seo-jin will play Sang-ha, a sprinter who never loses his smile even in difficult situations. Cheon Seung-ho, a member of the group THE MANBLK, will play Zhen-won, a hopeful who doesn't care about anything other than the marathon, and will work with Lee Seo-jin.