Puchimas!! Petit Petit iDOLM@STER: Fuyu-->Kotatsu<--Haru
Based on the 4-koma spin-off manga by Akane, serialised in Dengeki Maou since 2011. Takane does not want to put the kotatsu away, even though it's spring. This leads to a huge court battle lead by the Producer and Takanya, on whether the kotatsu should be taken away or not. Note: Bundled with the limited edition of the Puchimas! manga, volume 6. (Source: EN Wikipedia)
