Short answers, pulled from the story.
Keigo Chimoto first sketched the character for Street Fighter III: 3rd Strike with a directive to create a fierce, hot-blooded girl who embodied the concept of ikken hissatsu. The development team designed her with a barefoot, muscular physique and an oversized, loose-fitting karate gi that belonged to her deceased father.
Makoto was introduced in Street Fighter III: 3rd Strike as the first female character in the series to be designed with a deliberate lack of sexualization. Her story mode in 3rd Strike serves as the conclusion to her arc where her victory brings people to her door.
The yellow ribbon around Makoto's neck was a gameplay mechanic designed to telegraph her moves and demonstrate her speed. It fluttered to warn opponents of her incoming attacks and required new code to handle its physics in Street Fighter IV.
The development team used a specific Japanese Tosa dialect to give her a hot-blooded, regional flavor and distinguish her from other characters. The dialect was a crucial element of her identity that grounded her in a specific cultural context.
Makoto's gameplay was designed to be a rushdown character who relied on closing the distance and delivering fast, precise blows. She lacked the ability to produce large combos, forcing players to consider each move carefully and making her a challenging character for beginners to master.
In a 2018 worldwide poll, Makoto was voted the second most popular Street Fighter character. Capcom noted her as the most popular character in location tests for 3rd Strike in both North America and Japan.