Taste Sweet Love (2004)

Ma Young-hee has been secretly in love with her best friend, Han Jin-woo, for 8 years. Jin-woo, naively recognizing Young-hee as only a friend, asked Young-hee to let his runaway brother, Sun-woo, to sojourn in her apartment. As the two lived together, Sun-woo discovers Young-hee's unrequited love for his older brother, and saw the absurdity of how Jin-woo is unable to realize it and how futile are Young-hee's attempts to confess; Sun-woo pitied her and then gradually fell in love. But Young-hee still has feelings for Jin-woo despite him being beguiled by Young-hee's devious former classmate Jang Hee-won. Eventually Young-hee is left with the dilemma of choosing between the two brothers.