On the 2nd, the Seibu Lions Seibu Lions announced that they had applied through the Nippon Professional baseball Organization (NPB) for pitcher Kaima Taira 's transfer to Major League Baseball via the posting system, and that Major League Baseball had notified all MLB teams of the application.

Negotiations will begin on Monday, November 2, 2026, at 8:00 AM US Eastern Time (Monday, November 2, 2026, at 10:00 PM Japan Time).

Taira joined the Seibu Lions as a fourth-round draft pick in 2017. After making his first-team debut in 2019, his second year, he appeared in 26 games that same year, contributing to the Seibu Lions' consecutive league titles with 2 wins, 1 loss, 6 holds, 1 save, and a 3.38 ERA. In 2020, he appeared in 54 games and won the Rookie of the Year title with 1 win, 33 holds, 1 save, and a 1.87 ERA. Starting that year, he appeared in over 50 games for three consecutive years, and in 2022, he won the title for best reliever pitcher.

In 2023, he converted to a starting pitcher, pitching 150 innings across 23 games, achieving his first double-digit win season with 11 wins (7 losses) and a 2.40 ERA. In 2025, he appeared in 54 games as a reliever and recorded 31 saves, earning the title for most saves. This season, he returned to the starting rotation, pitching 146 innings across 23 games, and led the starting staff with a 12-5 record and a 1.36 ERA, securing the title for best ERA.