Can anyone answer me if manga is on going hoặc not !? Cause there is no update about it since months . Are they planning a tiếp theo season hoặc 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 tình yêu with Takano.
For other official news, i suggest bạn to tìm kiếm on twitter: @marukawashoten (sorry, the site it's only japanese)