Hong Seol, a student from a poor family, meets a rich Yoo Jung, who is her senior at her university. They both develop a rather inconvenient relationship after knowing each other.
Yoon-Jung accidentally calls a stranger, instead of her boyfriend, and has phone sex with the unknown man. When Yoon-Jung's relationship with her boyfriend turns sour, Yoon-Jung meets Hyun-Seung, the stranger she had phone sex with.
In order to inherit his grandfather's fortune, an incorrigible playboy agrees to teach high school for two years in Mr. Wacky, a bland, mostly irritating comedy from newbie director Kim Dong-Wook. To its credit, the film improves considerably in its second half, but by that time, some will likely find that it's a case of too little, too late.