San is an enthusiastic girl, with a large appetite. She often makes Forte bake or buy her food. One of her favorite hobbies is making Forte cross-dress. She does this by either tricking him, or by forcing him.
Forte and San are both examinees in the Magic Exam. When they learn that Nina has accidentally swallowed the Crystal Pearl, they kidnap her, planning to keep her for the remainder of the exams. While Sun was enjoying time with Nina, both of them eating cake together, Forte was complaining about having to watch over her for so long. When Sun heard this, she suggested they kill Nina and then extract the pearl.
San and Forte constantly go after Nina in attempts to get the pearl, but they always fail. Although Sun intends on killing Nina, she seems rather friendly towards Nina, and thinks of the exam as a game. San also seems to be rather good friends with Zero. She was rather pleased when they were paired together for the Kimodameshi, and the two seem to have a rather friendly relationship throughout the series.
In the sequel, Modotte! Mamotte! Lollipop we learn that two years after Zero and Ichi passed the exam, that Sun and Forte passed as well. They are now contestants in the Advanced Magical Exams. When they realize that Nina has once again swallowed the item needed to pass the exams, they plan to capture her, though this time they don’t intend on killing her. Instead, they explain that they will keep her in a giant bird cage until the end of the exam.
Sun, Forte, and the other contestants join Nina’s school to keep an eye on her and collect shards of the Crystal Drop when they get the chance. They play a rather minor role in the rest of the series.