Received: 13 August 2021
Accepted: 23 May 2022
First Online: 29 June 2022
: This study has been approved by the Scientific Research Committee at University of Tsukuba (The subject number is 23-146). All participants acknowledged their agreement to publish the results of the study after they were informed in writing and verbally that the study will be published in one of the refereed journals. This research project involved collaboration with eight public schools. The schools explained this project to parents, who provided informed consent on behalf of their children and obtained the agreement to participation in the study. All methods were carried out in accordance with relevant guidelines and regulations.
: Not applicable.
: The authors declare no competing interests.