Suika is sometimes nicknamed 'Watermelon' because Suika means watermelon in Japanese.
According to fans, Suika is considered the most flat chested Touhou character. Because of this, there are some fanart where Suika is STEALING other character's breasts.
Another ability of her is that you cannot refuse drinking sake from her. We can see this ability with Rinnosuke and Shikieiki (3rd and 4th Touhou M-1 Grand Prix) and with Aya Shameimaru (Touhou Fantasy Kaleidoscope 2: The Red Mist Incident)