An artist who created various paintings and sculptures. His full name is Weiss Guertena. At the beginning of the story, he is already deceased. Because he is referred to with male pronouns in the explanation of various works, and also because of things that a certain character says, it can be determined that he was a man.
With very few exceptions, he never painted living people; his artistic style is very particular, and possesses a gravity and charm that capture the hearts of those who see them. The people who are visiting his exhibition all adore his work.
On the other hand, he was a relatively minor artist and his art is only exhibited in small museums that don't have enough room to display all of his work.
It seems that he had a fair amount of money, and that there were people who were after his fortune. Also, it's possible to discern that he had a grandson.
It is said that Guertena did not leave behind any self-portraits, but...
Ib, the protagonist, has some exceptionally peculiar experiences at an exhibition of Guertena's work.