Talk:Kaiko/@comment-31023245-20170112010558/@comment-10733658-20170112011152

The most likely answer was to remove obstacles to their takeover, via Furuta. Early on in the series, we had that hint about internal strife. Marude knew about rumors of problems within the Washuu Clan, with discontent about the leadership of the main family and especially Matsuri. Even as an outsider, he knew that the Branch families were looking to oust Matsuri as the next in line for leadership.

And now we know those Branch families are, in fact, the members of V including the Garden kids like Furuta.

It's very likely that Tsuneyoshi was well-past his prime, being very old and inactive for a long period of time. He'd become too reliant on his bodyguards and servants, such that it was easy for Furuta to carry out the massacre and assassination.