the manga is about a boy who have a family that ownes a dojo. the dojo only haves i think it was 7 moves and only way of becoming the heir is to make a type of a sword move and they get only so many days or weeks to figurin it out and learn it and display it to the master of the dojo. The dojo is a family blood type of dojo so only the family can learn the swords moves and become the heir. the story is aroud the boy and how he becomes the master of the dojo.

If remember correctly in Gamaran, Mc's sword styles got 7 form too, at first he only mastered 5 form but through the story, his senpai brother-like teaches him another 2 form. Might be wrong though

Be kind or get banned

Read it, its kinda similar in some ways but not the one i was looking for. the main character lived in a proper dojo and his father is still alive in the manga i am talking about. but thanks for the one you said, totally forgot about that. will read it again ?