......I wonder how much longer can we stay together?

There is no more need to stick close to Ma-chan in order to rescue her

Our trainer and trainee relationship will one day come to an end as well

Our bonds, like everything else, will flow out to the sea

Gently, silently, coming to an end

That's the natural way of things

......So, Ma-chan is stuck

The way you kept resisting the natural way of things,