Can anyone answer me if manga is on going o not !? Cause there is no update about it since months . Are they planning a siguiente season o 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 amor with Takano.
For other official news, i suggest tu to buscar on twitter: @marukawashoten (sorry, the site it's only japanese)