Manu

Manu is Enu's father. Manu is represented by an elusive red-hooded figure throughout the majority of the game, up until the end.

Manu is also represented as The King depicted in the story found behind the Keyholes.

As the cloaked figure
The cloaked figure first appears in Denial. He can be seen in several places around the island; however, trying to approach him will cause him to disappear and then reappear somewhere else. He can sometimes be seen in doorways, once again turning and walking out of frame as soon as Enu gets too close. Nana can be seen sitting next to him in some places.

In the intermission sections between Anger, Bargaining, and Depression, Enu sees the cloaked figure with him on the boat. Enu attempts to call out to him, only for the cloaked figure to fall over the side despite Enu's efforts to save him. A piece of the figure's cloak is ripped away in the struggle, and this is implied to be where Enu got his red scarf.

The hooded figure was stated in an interview with Eurogamer to be a representation of guilt.

As the King
A massive throne can be found at the end of Denial and then at the beginning sections of each stage of the game. The throne in Denial is very clearly the King, but as the stages progress, the throne begins to become more and more similar in appearance to Manu, until we find him as himself in Acceptance.

A statue of the King can also be found at the end of Depression, which sits on the other side of a lighthouse structure from a statue of the weeping Prince.

As himself
It's only at the beginning of Acceptance that our perspective in the game flips, and Manu takes Enu's place on the boat. He calls out to his son in the same way Enu called out to the cloaked figure, and things progress the same way, with Manu attempting to pull Enu back on board only for the arm of Enu's raincoat to rip and be pulled into the ocean.

The throne we saw him in throughout the game becomes him sitting in his kitchen chair. He contemplates a key, which unlocks the door to Enu's room, and we follow Manu as he explores his son's things for the first time since his death.

We last see Manu embracing the spirit of his son and allowing the scrap of his raincoat to blow out the window, which earns you the story achievement Letting go.

Trivia

 * Manu’s name was revealed in an interview with Eurogamer.