Etymology: Derived from the Japanese elements 'masu' (益 or 正), meaning 'increase', 'benefit', or 'correct', and 'zo' (三蔵 or 蔵), which can mean 'storehouse' or refer to the Buddhist Tripitaka; more commonly in names, it may come from 'saburo' variants or 'masu' + 'zō' as an honorific suffix. Alternatively, it may be written with kanji like 正三 (masa-san, 'righteous third son') or 益男 (masu-o, 'increasing boy'), though the exact etymology varies by family usage.