A narrow-eyed, purple-haired young man who wandered into the strange art museum just like Ib. He is in his twenties (※).
Because he has very long bangs, his left eye is hidden, and the area around his eyes is shadowed. He has a few strands of hair that look like seaweed or eggplant leaves which are darker than the rest of his hair. He wears a shabby-looking, fringed coat (it was originally designed like that, and he has owned it for some time), and according to the official website he wears a tank top underneath.
When you examine a mirror in-game, Ib only comes up to his waist.
At the beginning of the game, his inventory holds a wristwatch whose hands don't move, a cigarette lighter he's been using for many years, a piece of lemon-flavored candy which he eventually gives to Ib, and a blue rose.
As with Ib, the rose is one with Garry himself, and if all of the petals are scattered he will die.
Garry's facial features are relatively androgynous, and he speaks in lavender linguistics, a very feminine speech pattern typical of some gay men in Japan. Apparently Garry is not very conscious of his own speech, and by the time he noticed he had just ended up with this way of talking.
On the official website, it is written that "his personality is a little womanly", but there is no further explanation.
His first-person pronoun is "atashi" (アタシ). He calls Ib "anta" (アンタ), and calls Mary "anata" (アナタ) during their first meeting, thereafter addressing her the same as he does with Ib.
Ib finds and rescues him when he is at the verge of death from a Lady in Blue stealing and playing with his rose. After this, they journey together.
He reads kanji that Ib doesn't yet know for her, and also helps move heavy objects, as he's strong despite his appearance. Also, he is mentally (or should that be physically?) stronger than Ib, and can endure for longer in hazardous places.
From the candy he carries and his happily discussing a store that sells delicious macarons, he is often perceived as a sweet tooth.
Because he has a lighter, it's theorized that he is either a smoker or was one in the past (though he is never shown with cigarettes in-game).
Apparently strange things (such as the blue doll and mannequins) tend to get attached to him easily.
His hobbies are taking walks and discovering hole-in-the-wall tea shops (※).
※The information about Garry's age and hobbies comes from the July 2012 volume of the anime magazine "PASH!".