Shirushi (シルシ, Shirushi?, lit. mark) is the third ending song for the Sword Art Online II anime adaptation, used starting from SII Episode 18. It was sung by LiSA, with lyrics written by LiSA herself, composed by Kayoko and arranged by Horie Shouta. The single of the same name is LiSA's 7th single and her first ever ballad single.