Light House Door "Locked"

[BlackWolf66]

I've searched the internet in general, Reddit, and here on STEAM... don't see any posts about this. Which seems strange that no one else has asked this. Anyway: In my game, when I go inside the Light House, I can see Wataru's living quarters and rooms, but the door to the far right that goes into the cylindrical Light House proper, cannot be opened. That is, I do not get an "interact" action. I'm in year 5 and have never been able to go inside the round part of the Light House itself. I'm guessing this might be linked to a heart level for Wataru... like if you get 8 hearts with him, he gives you a tour (LOL). Has anyone been able to access this? If so, how please.