Q:

Circle inside a circle character. What is it?

So I started playing Steins;Gate in Japanese the other day. And in one of the Tips about a character from the 雷ネット翔 , キラリちゃん is described as

頭が良くて、スポーツ万能。しかもカワイくて性格も〇

(But inside of 〇 is another circle...)

I don't know how to pronounce it and what it means...

A:

After doing some investigation, it seems that there are two Unicode characters which are made of a circle inside another circle:

◎ U+25CE BULLSEYE
⭗ U+2B57 HEAVY CIRCLE WITH CIRCLE INSIDE

In this Japanese context, only the first one ◎ appears to be appropriate (Wiktionary), since it is known as 二重丸【にじゅうまる】 and is defined as 「とても良いことを示す記号。」, which suggests that it is indeed a stronger (double) variation of the more commonly used symbol ○ 丸【まる】「良いことを示す記号。」(Wiktionary).
So, 性格も◎ can probably be understood as something like "very good character too"...

