Saiichi MARUYA deepened this supposition in a conversation with Sususmu ONO, and argued the following two points:(1) Group b is centered on Utsusemi, Yugao, Suetsumuhana and Tamakazura, and it has a commonality in that these chapters depict the failure of Genji's love;(2) Its writing style is more sophisticated than that of group a, and it has more deepened descriptions, which means after the first part of the group a gained a reputation, group b was written this time to describe the human touch of Hikaru Genji, who was like a perfect hero in the fairy tale (Genji in group a was described as such).
丸谷才一は大野晋との対談でこの説をさらに深め、(1)b系は空蝉、夕顔、末摘花、玉鬘を中心に源氏の恋の失敗を描いた帖であることが共通している事、(2)筆がa系よりもこなれており叙述に深みがある事などの点から、a系第一部の評価が高くなったのちに、今度は御伽噺の主人公のように完璧な光源氏（実際にa系の源氏はそう描かれている）の人間味を描くために書かれたのがb系ではないかと述べている。