Hey Massaki,
there are various ways in which to build page web layouts; Kanso comes with a multitude of shortcodes, including a columns shorcode, that have been designed to fulfill this role. Please refer to page 11 and Appendix 2 of the theme manual for more detailed information on how to use the shortcodes. In case you face any issues, do not hesitate to contact me!
Sincerely,
Andrii / Satori Studio