病名恋ワズライ (Byoumei Koi Wazurai)

Background
This song was uploaded onto Niconico Douga and YouTube on December 17, 2013. It has entered the Hall of Fame on Niconico and reached over a million views in it's YouTube upload

It's part of Honeyworks' Confession Executive Committee Love Series and it's about Natsuki's feelings for Yuu, taking place before the events of Kokuhaku Yokou Renshuu.