My Whispering Plan (2002)

Introvert and plain-looking Jane and beautiful Miss Sunshine Sunny are classmates and inseparable best friends who share all of their deepest secrets. In Jane's mind, not only are they as close as sisters, she is also like a guardian angel who protects Sunny. Because Sunny's parents are constantly busy and never home, Sunny often stays over at Jane's house. Before long, she becomes part of Jane's family. The two girls construct a fancy and extravagant imaginary world with comics and role-playing games, in which Jane is deeply engrossed. There are too many things in Sunny's life that could divert her attention from her friendship with Jane. To compete with her other friends, Jane tries hard to maintain their camaraderie, but her over-the-top efforts are often ignored and neglected. Sunny begins to resent Jane's possessive friendship. One unwitting betrayal to Jane? When Sunny regrets, Jane is no more her guardian but phantasm.