From 16 March, limited expresses Hokuto (Hakodate-Sapporo), Suzuran (Sapporo-Noboribetsu/Muroran), Ozora (Sapporo-Kushiro) and Tokachi (Sapporo-Obihiro) will be going into limited full reserved seats only mode (similar to Narita Express).
In addition, the number of reserved seat cars in limited expresses Lilac and Kamui (Sapporo-Asahikawa) will increase from 1 to 3 in a 5-car set.
Source: https://www.jrhokkaido.co.jp/CM/Info/news_en/pdf/all_reserved_202311_en.pdf
by mithdraug