We don't have synonyms for manju yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are manu, mangu and manji.
(n) :
A traditional Japanese confection; most have an outside made from flour, rice powder, kudzu, and buckwheat, and a filling of red bean paste, usually made from boiled azuki beans and sugar; in Hawaii, Okinawan ones are made with a filling of purple sweet potato, butter, milk, sugar, and salt, but the most common filling is bean paste.
(n) :
A traditional Japanese confection; most have an outside made from flour, rice powder, kudzu, and buckwheat, and a filling of red bean paste, usually made from boiled azuki beans and sugar; in Hawaii, Okinawan ones are made with a filling of purple sweet potato, butter, milk, sugar, and salt, but the most common filling is bean paste.