Among them, Soshun TAKEDA proposed that the first part should be divided into 'Murasaki no Ue Series' and 'Tamakazura Series,' linking to it his theory of composition (a theory that the Tamakazura series was inserted into the work later).
このうち第一部は武田宗俊によって成立論（いわゆる玉鬘系後記挿入説）と絡めて「紫の上系」の諸巻と「玉鬘系」の諸巻に分けることが唱えられた。