I read a book when I was young about a male main character (I vaguely remember his name to be something similar to Maria, or starts with M, might be wrong) who arrives at some sort of hotel at a seaside and explores it to investigate some sort of super natural things going on inside. There was also a character who was called a Captain.
The book art gave a bit of a Gothic cartoon vibe, featuring a drawing of the main character with the building behind I think. The book is in English.
I believe this is also part of a series, as I remember reading more than one book about this character. I read this book around ~7 to 10 years ago when I was still a young kid, borrowed it from a local library.
Does anyone know what this is?