S1, E2: Tata begins cleaning up the flat to welcome Mei home, but Kuma messes up the room when looking for his favourite socks - meanwhile, Dr Ding Ding and the Mouse Commandos are messing around in the bathroom. Tata decides to carry out his cleaning mission on his own, but it is difficult to make progress with the others around - to make matters worse, the flat's ceiling - shared with the mysterious neighbour upstairs - collapses and turns the whole flat into a swimming pool!