Archaic term for a love letter, especially in classical or historical contexts. Modern Japanese uses ラブレター or 恋文.
In Heian-period tales, scenes of exchanging love letters often appear.
Compound of 懸想 (kesō, 'being in love; longing') and 文 (fumi, 'letter'). The exact historical derivation is uncertain, but the term is firmly associated with classical Japanese literature.