So, anyone know what's the joke with Yazawa?
She's Yua's childhood friend. For a hot second, Reina thought she was a competitor for Yua, now she's become a wiki page for Reina to access for getting to know Yua even more.
The "Yazawa" thing is a trend/affectation some gals get into, because being cutesy is a number one goal. I've always thought that it was either mimicking grade schoolers or Pokemon, not sure if either is accurate.
Source: wife is big into gal culture, and one of my best friends' little sister was a gal throughout Middle School though University, so I got to experience a bit of early 2K gal culture when I lived with my best friend in Japan for a year.