All credit goes to whoever did the Amagami SS+ OP – Check My Soul sheet music. I don’t know who it was, since no source is listed or mentioned in the OP/ED guidebook that came with Amagami SS+ Amakunison Pack. The only information about this song that’s floating around on the internet is that Amagami SS+ OP – Check My Soul was composed by Hiromi Mizutani.
Lee Hi is an South Korean singer under YG Entertainment. Lee Hi was first heard of in 2009 by her 1st mini album First love where she sang the main track “1년の幸せ”. Lee Hi first debut with her single “1년여가의 행복” on October 28, 2012. Lee Hi released her first full-length album titled “First Love”