The opening song from Season 1-- Monochrome no kiss （SID）
I have found the piano version, I used to use scribd to upload the PDF file, but it seems a lot of trouble to go through. think I will just let you know that I have it, if you want a copy, leave a comment with your email, I will send to you. It seems a lot easier this way. Please follow my page and let me know the song your want for piano sheets, I will try looking for you. Cheers!