The cultural psychology of romantic relationships is relatively understudied. To redress this lacunae, the present study examined the Japanese concept of ‘amae’, or the state of expecting a close other's indulgence when one behaves inappropriately, within the day-to-day relationships of 30 Japanese undergraduate romantic couples. For 2 weeks, both partners completed daily diaries that assessed their amae behaviour (requesting, receiving, and providing amae), relationship quality, conflict, and motivation to enhance closeness. Results revealed that amae behaviour was associated with greater relationship quality and less conflict. The motivation to enhance closeness partially mediated the association of amae with relationship quality.