Midare was very over-confident in his and Shigure's abilities. He talked down to the Three Sand Siblings for trying to challenge his team.
Midare and his team had the misfortune of confronting the Three Sand Siblings during the second phase of the Chūnin Exams. Shigure sought Gaara's scroll and underestimated his power. Shigure attempted to use his Senbon Shower technique but Gaara's sand protected him. Gaara then took the opportunity to confine Shigure and his team using the Sand Binding Coffin. Gaara then crushed the Ame genin, killing them.
Midare when translated can mean "Early Summer rain Storm".