Fude Pen ~Ball Pen~ (YuiAzu Ver.) (ふでペン ~ボールペン~ (ふでぺん ~ぼおるぺん~)(ゆいあずVer.) Fude Pen ~Ball Pen~ (YuiAzu Ver.)) or Calligraphy Pen ~Ballpoint Pen~ (YuiAzu Ver.) is an "Insert Song" and alternative version of Ho-Kago Tea Time's song Fude Pen ~Ball Pen~, performed by Yui Hirasawa and Azusa Nakano, produced by Pony Canyon and published on the sixth of October 2010 within the second Original Soundtrack album of the second season of the anime. The song was sung by Yui's and Azusa's voice actresses Aki Toyosaki and Ayana Taketatsu.