The song will be a tie in for the OAD anime adaptation of "Kimi no Iru Machi" (君のいる町) as the ending theme and Mano will also voice one of the female characters.:
Picture of the cast:
Also in case you missed them here are the covers to the single:
Single V Version.
and the MV for Doki Doki Baby!
Doki! Doki! Baby! / Tasogare Kousaten are out on wedenesday the 22nd of February.
Source: ManoerinaCHANNEL 1 and 2, KODANSHAcojp, Moca News and Amazon.co.jp 1, 2, 3, 4 and 5