It is a hammer; the sounds that it makes are intentionally reminiscent of the hammer from the game "Donkey Kong". Also, mallets that are used for playing chimes are made from a hard plastic, not from metal.
hammer.... u touched my heart, that voice, that acting, that performance!!!!... its angelic... hammer have a lot of potential to become the greatest artist in history!!!!!!!
@jarrodocus Hammer's rather big on Touhou, and Sakuya's his favourite character. Thus, he's allowed to sneak in referrences to Sakuya's theme whenever he plays a song because the fans love it.
Phew! Thank God for this video. I JUST came from the wierd/dark part of youtube ( where there are the haunted things, creepy subliminal messages, horror songs, and satanic evidence O_o) and got too scared LOL