itch.io

That wall is to unlock the katana-tan. You need to have the seal/dragon. The seal is the “eros 420” logo in the right bottom of the screen. It’ll be gone once you have seg. Solution: start a new game (applies to ng+ and curse mode) and beat the game with no seg. Once you get all the echoes, including white, that part of wall will change. Just try it out yourself