- 03.01.2001.-02.28.2021.: Working at 6 schools other than Geomdan Elementary School
- 03.01.2021.-02.28.2022.: Dispatch to Incheon Education Training Center (Topic: Peaceful unification education program linked to East Asian civic curriculum)
- 03.01.2022.-02.28. 2023.: Working at Jangseo Elementary School in Incheon
- 03.01.2023.-Present: Working at Keonguk Elementary School in Japan