The staff of The Apothecary Diaries Season 2 announced Toshiyuki Toyonaga is joining the cast of the anime in episode 42 as the character Lahan. Lahan is the adopted son of Lakan.

The second cour of The Apothecary Diaries Season 2 began on April 4 with episode 37. The anime’s new opening theme song “Kusuhiki (Mysterious)” by Mrs. Green Apple and new ending theme song “Hitorigoto (Soliloquy)” by Omoinotake.
The Apothecary Diaries Season 2 airs weekly on Fridays at 9:15 a.m. PT / 12:15 p.m. ET on Crunchyroll. In Japan, the anime airs at 11:00 p.m. JST on Nippon TV’s FRIDAY ANIME NIGHT programming block.
Square Enix recently announced The Apothecary Diaries will receive a new spinoff manga series focusing on Xiaolan, maidservant of the palace and Maomao’s close friend. The manga is titled The Apothecary Diaries Side Story: Xiaolan’s Memories, and it will be illustrated by Itsuki Nanao.
The first cour of The Apothecary Diaries Season 1 ran for 12 episodes. The second cour ran for another 12 episodes, bringing the first season’s total to 24 episodes on March 23, 2024.
Lastly, here’s a synopsis of the series, via Crunchyroll:
Maomao lived a peaceful life with her apothecary father. Until one day, she’s sold as a lowly servant to the emperor’s palace. But she wasn’t meant for a compliant life among royalty. So when imperial heirs fall ill, she decides to step in and find a cure! This catches the eye of Jinshi, a handsome palace official who promotes her. Now, she’s making a name for herself solving medical mysteries!