|~ Mina Beff's introduction quote in almost every episode|
Mina is Trina’s best friend in fact, her only friend. Trina is very rude and abusive to Mina and treats her like a slave. Mina's original name was Bernadette, but Trina forced her to have her name legally changed to Mina so their names would rhyme. Although Mina is always getting stepped on by the bossy Trina, she enjoys the "rub-off" popularity she gets for being by her side. In the episode "Space Jammin'," it was revealed the Carrie is Mina's little sister. Although it has never been seen much in the show, this means that they must have a strong relationship with each other.
In the episode "A Knight to Remember", she becomes the main villain after a comet has passed. Mina then became a bratty princess with Trina as her right-hand girl. After an actual giant knight crashes the party, she demanded others to stop it, showing no regard for their lives. Eventually, she goes into Diary mode (similar to Trina's). When the comet passed again, she and Trina went back to their normal selves. She got chased by Trina afterwards.
In the episode "Hear Us Rock, Part 2", Mina became fed up with being pushed around and bullied by Trina, so she stood up to her and took charge, making her the one on top while Trina was her abused sidekick and slave. It is unknown if this relationship will continue on like this in the second season of Grojband or if Trina will go back to being the one on top after this.
Mina has dark, teal, blue hair and black spectacles. She wears an orange turtleneck sweater and dark, brownish, green shorts. She wears long, white knee socks and black shoes.
She is a nice, shy, and timid girl that is loyal to Trina and does whatever she commands. According to the series creators, she and Trina genuinely care about each other (having been friends since kindergarten) and Mina endures all Trina's abuse in hopes that Trina will one day go back to being the nice person she used to be. Mina is a really nice and selfless girl who is always being nice to anyone no matter who they are and what they do. She seems to be friends with Trina and at the same time, is being nice to her worst enemies. She doesn't seem to care when she gets abused and hurt, which is seen mostly when it shows how terribly Trina hurts her. No matter how much she gets disrespected by someone, she will always continue to respect and be nice to that person. She is also very intelligent and great at math she is a super nerd who is part of the nerd club at Elementary High.
- She is similar to Mr. Smee from Peter Pan, Phoebe from Hey Arnold!, Mr. Snoops from The Rescuers, and Beth from Total Drama as they all have the same personality sometimes, wear glasses, and whenever they both got abused by their bosses, they don't retaliate whatsoever.
- That Mina is devoted to the point of being almost in love with Trina despite the abuse she suffers is similar to the relationship Waylon Smithers has with Mr. Burns.
- Her loyalty to Trina in hopes that she will become kind again also calls to mind Wormmon and the Digimon Emperor.
- Mina's name was originally "Bernadette" but when she became friends with Trina, she forced her to legally change her name to Mina so that their names would rhyme.
- Mina's design was based off of Velma from Scooby-Doo.
- She has the same hairstyle as her sister. They are similar in color as well.
- Mina is voiced by Denise Oliver, who also voiced Maurecia from Wayside, Kitty Ko from Sidekick, Hazel the Squirrel from My Friend Rabbit, Yu from Beyblade: Metal Fusion, Gwyn from Looped and Patty from Fangbone.