The main character is Thomas. And as for the children, we don't know their exact number or their individual names. They are likely to be the ones who Thomas has some kind of relationship with, whether it's a mentoring relationship or they are all on an equal footing in the story. There might also be a sidekick - like character for Thomas, like a little animal that the children love, which could also be considered an important character in a way.
Obviously, Thomas and the children are the main characters. But without more context, we don't know if there are other important figures in the story.
The best chapter pointer here is Chapter 31, "Master, I've been having some bad luck lately!". It opens with Before Shen Lan had reached the backyard, she already heard the sounds of... and closes on After staying in the study and reading for another day, she finally....
A practical answer is Chapter 33, because it turns the idea into a concrete scene. The chapter opens with Following the announcement, five artists respectively reposted the Weibo—..., adds pressure through With a sister looking like that, how good can he look?], and ends on Although Su Yinwan was.
Look to Chapter 60 for the clearest answer. It begins with What's with Jiang Yan, treating his own sister Jiang Li like this?" "He..., keeps building through When Jiang Li found a place to live, she didn't bother with him either,..., and lands on And in traditional characters?" "What else?.
The best chapter pointer here is Chapter 34, "Official Recording!". It opens with Seeing that the public sentiment wasn't quite right, Su Yinwan felt... and closes on Now that Lili is misunderstood, they start to kick us while we're down."....
The best chapter pointer here is Chapter 20, "Miss Su, your defense is somewhat clumsy". It opens with Several people turned their heads upon hearing the sound and saw three... and closes on So, he turned and questioned Jiang Li..
The best chapter pointer here is Chapter 23, "Became Trending for Being Scolded". It opens with Although Jiang Li exerted very little strength, Jiang Yan instantly felt... and closes on However, just as she buried herself in the study, pouring over mysticism....
A practical answer is Chapter 1, because it turns the idea into a concrete scene. The chapter opens with Jiang Li, I'm warning you, don't set your sights on Yinwan anymore, or..., adds pressure through Coming to his senses, he also switched to a kindly smile, "Alright, girl,..., and ends on Yet.
The best chapter pointer here is Chapter 14, "She Looks So Cool Dancing with a Gun". It opens with Lin Manru had a rare good night's sleep. and closes on But clearly, Lin Manru was unable to accept that her delicate daughter had....
A practical answer is Chapter 35, because it turns the idea into a concrete scene. The chapter opens with Shining Transformation Trip's filming location was set on the distant..., adds pressure through They even momentarily forgot the real reason they were squatting in her..., and ends on Brother.