http://www.tsunku.jp/take1.htm
A cover album of songs composed by tsunku (morning musume's producer, whom also sang Love~since 1999~ with Ayu) to be sang by himself will be launched on Feburary 18th. Tracklist is available on the URL on top and according to the list,
Takahashi Ai, the 4th generation member of Morning Musume will be covering Ayu's part in this song in this album.
Incidentally Tomoya Nagase's Hitoni batchi no brush (toothbrush for one), which he sang in the identity of the lead actor in the dorama Mododake, will be covered also.
Other songs in the tracklist also expectedly includes some morning musume's numbers. Do remember that all songs will be sang personally by himself. ^^