Amayo is the ex-wife of Michiru Tsuki and the mother of Hikaru Tsuki.

She greets Hikaru after his world trip, but has difficulty recognising her fattened ex-husband. She breaks into an argument with him telling him that there is something more important than money, something that only made her angrier at him when he tried to offer her materialistic goods as a way to make up. As Ishidate is defeated, Michiru realises that she was telling him the most important thing is protecting his loved ones.

(Source: wikia)