ちなみに男だと断言できた理由は
「家に寝泊まりするくらい仲の良い女友達なんて
　私以外にいるはずない」
だとかなんとか

メリーさんの電話＞post #1923261

By the way, the reason she was able to conclude that it was a man was
"Besides me, there's no girls she's friendly enough with to have a sleepover with."
...or something like that.

Merry-san's call＞post #1923261