Yonatan comes to MIT from the Oklahoma School of Science and Mathematics in Oklahoma City. Before enrolling at the Oklahoma School of Science and Mathematics, Yonatan attended Classen School of Advanced Studies in the ninth and tenth grades where he also played basketball for the school team. Although the School of Science and Math did not have a team, Yonatan played outside of school at local gyms and for his church basketball team. Yonatan was captain of his church team for two consecutive years and led the team to the Diocese of Denver tournaments held in Tulsa, Oklahoma and Ogden, Utah. He was presented with the MVP award at the second tournament held in Ogden.

Yonatan is the proud son of Elsa Teklemariam and Tekleab Tsegay. Tekleab works as a geological engineer and Elsa as an accountant both for the State of Oklahoma. Yonatan intends to major in Aero/Astro engineering. Yonatan is also a member of detachment 365, the Air Force ROTC unit at MIT. He would like to become an experimental test pilot and eventually an astronaut. In his spare time, Yonatan enjoys sleeping, playing sports, and going out with his friends. He has a 14 year old sister and an 8 year old brother.