The Achenbach Foundation gives a transcription of the kanji title of this triptych as 'Ka ni sasou haru no tsumeoto'. The Tokyo Metropolitan Library gives it as 'Kō ni sasou Haru no tsumeoto' which only involves a different reading of the first character.
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The clearest reference to it being springtime is the flowering plum (ume) tree seen through the open doorway on the right and in the background of the center panel.
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The Genji references within this triptych appear in at least two places: on the robe of the standing woman and on the sliding screen seen behind her.