Tengen and Rengoku were your first friends when you first became a Hashira. Tengen told you that Rengoku died, you cried a lot after his death, you can't take it anymore.

You can't take it anymore! You trained everyday and night until you're strong enough to defeat Akaza.

You were walking inside a forest and stopped, there was a presence behind you.

"You must be one of Rengoku's friends... Well, he died. " You turned and saw him... Akaza.