Stephanie Hym Lee (née Bell; born April 16, 1989), better known by the ring name Mia Yim, is an American professional wrestler. She is signed to WWE, where she performs on the SmackDown brand under the ring name Michin ( MEE-chin, Korean: 미친, lit. 'crazy').

Bell is also known for her time in Impact Wrestling, where she is a former Impact Knockouts Champion, and during her first stint there, performed under the ring name Jade and was a member of The Dollhouse stable alongside Taryn Terrell and Marti Belle. She has also performed for Combat Zone Wrestling (CZW), Shine Wrestling, and Shimmer Women Athletes. In Shine, she has held both the Shine Championship and the Shine Tag Team Championship (with Leva Bates). In addition, she has wrestled in Japan for Reina Joshi Puroresu.

Bell signed with WWE in 2018 after an impressive performance in the second Mae Young Classic, and was assigned to NXT. She joined the main roster in 2020 and became a part of Retribution under the ring name Reckoning. She was released in 2021, and briefly returned to Impact Wrestling and the independent circuit in 2022. She returned to WWE in November of that same year and subsequently joined The O.C. until the group's disbandment in mid 2024.