May I ask the title of the book that you are referring to?
The fact that you said that you had to look up the kanji suggests to me that the name is transcribed in the Latin alphabet and if it is transcribed as 'Otoko', then it does leave a bit of room for interpretation as to how the name may have been written.
I used four main sources to find out whether 桜桃子/櫻桃子 is used:
http://www.douseidoumei.net/ (taken from telephone book data, sort of overall population)
http://www.namaejiten.com/ (Heisei period data)
FamilySearch
Google (by searching "[insert kanji here] [insert kana here] pdf ふりがな]" - kanji or kana can be searched on its own")
None of these main sources are able to find 桜桃子/櫻桃子 at all with the reading Ōtōko (the first two sources don't even have 桜桃子/櫻桃子 listed), hence why I removed the entry.
The only example of 桜桃子/櫻桃子 is here (in Japanese):
https://ja.wikipedia.org/wiki/%E6%88%90%E7%80%AC%E6%AB%BB%E6%A1%83%E5%AD%90The given name is listed as Ōtōshi/Outoushi (おうとうし) and that name was not even his real name, as the article notes that 冨造 (I can only guess, it's Tomizō) was his real given name.
On Jisho, there are two other readings for 桜桃子/櫻桃子, Otoko and Yuzurako, and these two readings would hypothetically be more likely choices than Ōtōko/Outouko.
My PNL:
http://www.behindthename.com/pnl/149249'Maybe It Is Daijiro (aka
Maks)' blog:
https://maybeitisdaijirou.wordpress.com/'Beyond
Sakura and
Hiroshi' blog:
https://beyondsakuraandhiroshi.wordpress.com/My Twitter: @maybeitsdaijiro
This message was edited 10/12/2019, 4:29 PM