Can anyone answer me if manga is on going ou not !? Cause there is no update about it since months . Are they planning a suivant season ou what ????

The manga it's on going, don't worry.
On the december issue it's released chapther 20 of "Onodera Ritsu no Baai". So, be needed only 75 days to Ritsu for to be fully to fill in l’amour with Takano.
For other official news, i suggest toi to chercher on twitter: @marukawashoten (sorry, the site it's only japanese)