The main purpose of the present study was to elaborate on coping behavior toward romantic break-ups, and to examine the relationship between coping and mental health. First, in order to establish the items for this study, a pilot survey of 950 undergraduates was conducted in order to collect free responses describing coping behavior toward romantic break-ups. Second, 455 undergraduate students completed scales for assessing coping behavior, the extent of romantic love toward the ex-partner, and mental health (duration of recovery period from the break-up, and the resulting distress). Factor analysis of the coping items produced six factors : Regret, Grudge, Dissolving Relationship, Positive Reappraisal, Displacement, and Distraction. Structural equation modeling was conducted, suggesting that coping behavior influenced mental health even after the effects of the recovery period were controlled. It was also found that Regret and Grudge/Dissolving Relationship influenced mental health negatively.