At the end of the volume 4 of Tokyo Ghoul, Ishida included this self portrait of him drawing Darth Vader. In one of the Young Jump interviews when asked who his ideal father would be, Ishida responded with ‘Darth Vader’. Why is this relevant? Because Tokyo Ghoul references a lot of classic literature, and if you consider anything that has a profound and lasting effect on a genre of storytelling that is immediately recognizable as a classic, then Star Wars could also qualify under that label.
If you were to comb through Tokyo Ghoul for Star Wars, or ideas that occur in Star Wars as a motif to be referenced in Tokyo Ghoul you’d find the works actually have a quite a few points in common. Particularly in a few areas.