Azusa has much shorter hair than Ayumi does, so I would use that to try to differentiate them. I don't think Aya's vision is as bad as Nekonyaa's; in official art, her glasses don't seem to create a significant amount of distortion.
Ah hah hah hah,
I to~tally can't tell the difference between Saki and Karina!
How to Tell Them ApartAya,
are you wearing contacts?Ah,
is Saki the one with the slightly larger breasts?Where's Azusa?
Blurry~…
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a
t
Although,
I can't even tell Ayumi and Azusa apart~Aya~!!Pat
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No,
my glasses are just being repairedThe taller one must be Ayumi!Oh my!I can't see any~ thingHuh?
Which one's taller...?
And did Ayumi have an ahoge?Pat