- 2022/04 - 現在 The University of Tokyo Graduate School of Humanities and Sociology Associate Professor
- 2024/08 - 2024/09 Universität zu Köln Historisches Institut, Philosophische Fakultät (Arbeitsstelle des Projekts “Edition der fränkischen Herrschererlasse”) Gastforscher
- 2023/08 - 2023/09 Universität zu Köln Historisches Institut, Philosophische Fakultät (Arbeitsstelle des Projekts “Edition der fränkischen Herrschererlasse”) Gastforscher
- 2022/04 - 2023/03 Aoyama Gakuin University College of Literature, Department of History Parttime lecturer
- 2021/10 - 2022/03 The University of Tokyo Faculty of Letters, Division of the Humanities, Department of Occidental History Parttime lecturer
- 2021/09 - 2022/03 Sophia University Faculty of Humanities Department of History Part-time lecturer
- 2015/04 - 2022/03 Aoyama Gakuin University College of Literature, Department of History Associate Professor
- 2021/04 - 2021/09 Gakushuin University Faculty of Letters, Department of History Part-time lecturer
- 2019/04 - 2020/03 Freie Universität Berlin Friedrich-Meinecke-Institut Gastforscher
- 2015/04 - 2015/09 Komazawa University Faculty of Letters, Department of History Part-time lecturer
- 2014/09 - 2015/03 Japan Women’s University Faculty of Humanities, Department of History Part-time lecturer
- 2014/05 - 2015/03 The University of Tokyo, Graduate School of Arts and Sciences Department of Area Studies Project Researcher
- 2014/04 - 2015/03 Dokkyo University Faculty of Foreign Languages, Department of German Part-time lecturer
- 2013/04 - 2015/03 Rikkyo University College of Arts, Department of History Part-time lecturer
- 2013/04 - 2015/03 Edogawa University Part-time lecturer
- 2013/04 - 2015/03 Graduate School of Humanities and Sociology, the University of Tokyo Researcher
- 2014/04 - 2015/01 Rikkyo University the Department of History, College of Arts Research assistant
- 2014/04 - 2014/09 Komazawa University Faculty of Letters, Department of History Part-time lecturer
- 2013/05 - 2013/12 Rikkyo University the Department of History, College of Arts Research assistant
- 2012/07 - 2013/03 Center for Evolving Humanities, Graduate School of Humanities and Sociology, the University of Tokyo Researcher
- 2012/07 - 2013/01 Monumenta Germaniae Historica (Munich, Germany) Visiting scholar (supported by the Program for Evolving Humanities and Sociology, the University of Tokyo)
- 2011/07 - 2012/12 Ludwig-Maximilians Universität München, “Herausgabe der Urkunden Kaiser Friedrichs II.” Research assistant
- 2010/12 - 2012/03 Center for Evolving Humanities, Graduate School of Humanities and Sociology, the University of Tokyo Researcher
- 2011/03 - 2012/02 Monumenta Germaniae Historica (Munich, Germany) Visiting scholar (supported by the Program for Evolving Humanities and Sociology, the University of Tokyo
- 2010/03 - 2011/12 Bayerische Akademie der Wissenschaft, “Repertorium: Geschichtsquellen des deutschen Mittelalters” Research assistant (Wissenschaftliche Hilfskraft)
- 2010/04 - 2010/07 Project “Carolingian Canon Law” Research assistant (supported by LMU München)
- 2004/04 - 2005/03 Graduate School of Humanities and Sociology, the University of Tokyo Teaching assistant