The main character is the Digimon Cyber Sleuth. There are also other important characters like various Digimon that the sleuth befriends and teams up with during their adventures in the digital world.
The plot involves the main character getting involved in the digital world as a Digimon Cyber Sleuth. They have to solve various mysteries and face different challenges related to Digimon. There are often battles against rogue Digimon and uncovering secrets about the digital realm.
The length of Digimon Story Cyber Sleuth can be quite subjective. On average, it might take you 25 to 35 hours to complete the main story. However, if you want to complete all the side quests and collect everything, it could easily extend to 50 or more hours.
The day one Digimon are usually found in specific areas or quests within the game. You might need to complete certain tasks or explore certain locations to encounter them.
I don't have the exact number off the top of my head. But you could try looking it up on dedicated gaming databases or asking other avid players of Digimon Story Cyber Sleuth.