I think 'Demon Slayer' might be a good choice. Both have intense action scenes and a bit of mystery. Also, the art styles are somewhat comparable.
You might like 'My Hero Academia'. It shares the theme of characters with special powers and facing various challenges, similar to the ones in 'From the Red Fog'.
The Red Fog manga is appealing because of its unique plot and interesting characters.
The adaptation of 'From the Red Fog' manga is praiseworthy. It stays true to the core of the original, with only necessary tweaks to make it suitable for the specific format. The fans have mostly appreciated the efforts put into it.
One of the main characters is a mysterious figure who seems to have a connection to the source of the red fog. His actions are often shrouded in mystery and his true identity is gradually revealed throughout the story. He has unique powers that set him apart from others and his decisions have a major impact on the events that unfold in the novel.
There are several manga that share similarities with Red River. For example, 'Fushigi Yûgi' has elements of adventure and romance like Red River.
Well, 'Fruits Basket' might be comparable. Both have elements of emotion and character development that could appeal to fans of Red Candy. It also has a touch of fantasy and relationship dynamics.
Manga like 'The Rose of Versailles' and 'The Twelve Kingdoms' might appeal if you enjoy 'Red River'. 'The Rose of Versailles' has historical drama and powerful female characters, and 'The Twelve Kingdoms' offers a rich fantasy world-building.
I'd recommend 'Fushigi Yûgi'. It shares the theme of epic quests and characters facing various challenges, similar to Red River. Also, the character development and world-building are quite engaging.