so if Hama chan's dad is grey, Hama chan's mum is apparently now grey, and yume's mum is grey... then what about yume's dad? I can't remember what they said about him.
Nothing, really. A lot of emphasis has been placed on Yume and Hama's moms, who are grey and in the case of Hama's mom, went out of their way to become grey to get eternal life.
They both seem to do the overlapping thing, but Yume's mom seems to be able to do it more successfully as Chacha than Hama's mom can? If she even can at all?
Also, not related to the above, I like that this mixup was foreshadowed at the beginning of the Kuroiwa job. Hama asks Yume about Nishimura, but doesn't know her name. Yume gives Hama a nickname that Hama sticks with this entire meeting. Combine that with all other times where Hama is around when Nishimura is in conversation with Nishimura not being named, it seems like Hama is just being forgetful. But we didn't expect HOW much she forgot about Nishimura.
It also ties into how Hama uses nicknames for pretty much everyone she's close to. She never really says Yume's surname, it's always Yume. A lot of people use nicknames to help them remember others, but they obviously don't have Hama's problem.
I'm probably just rambling.
I'm still not at the level of Old Man Yagi.