Chinatsu and Tatara are not splitting up. They're a mirror of Sengoku and Chizuru. They're an underdog pair - everything about them should mean that they crash and burn, but its exactly their differences that lets them thrive and feed off of each other. We wouldn't have had such a painstakingly emotional previous arc, with Chinatsu kicking down the door to Fujita, if it was going to end in them breaking apart. Tatara needs to realise that his reason for dancing is no longer Shizuku, he has personal issues to overcome with his family and injury too, he's going to clam up but its Chinatsu's bullheaded personality that's going to break the clam apart. They need each other.