Reddit mentions of Happy Candy

As /u/eureka7 said, unfortunately Housei hasn't released a lot of original music, I think he has too much fun covering other's songs in karaoke contests etc. heh. I really wish they'd put out a Yamasaki Produce CD with the original draft songs he sung that the other guys used for rehearsals.

So as eureka7 found, he did compose a debut album for AiAi, here's the tracks:

• Telephone
  
• 青神
  
• 青神（OnigoeMix）
  
  According to his Japanese Wikipedia, he also composed some songs for Ayumi Murata (村田あゆみ) back in 2007 (three weeks after being hospitalized for that intestinal problem mentioned in the Hospital batsu). They were to be used as insert songs on the radio show he was on at the time.
  
  
• 伝説の狼 "Wolf of Legend"
  
• The other track Birthday, I can't find, though there's a short sample on the Amazon page for the album (track 10).