Katherine James, of Santa Barbara, California, says she was shocked when she was diagnosed with stage 3 breast cancer at the end of the last school year. But the beloved fourth-grade teacher has received some much-needed encouragement from her students, who recently showed up at her home to celebrate her final chemotherapy treatment.

James, 55, wasn’t expecting to turn down her road on the afternoon of September 11 and see a crowd of students and parents holding signs and ringing bells to commemorate the milestone.

“They were standing in the streets and I recognized some of the moms’ cars. I was very touched,” James, who has taught at Mountain View Elementary School for over 20 years, tells PEOPLE. “I was just really warmly surprised and it was a very heartfelt moment. I had tears in my eyes.”

Shortly after her diagnosis, James underwent a double mastectomy and had chemotherapy over the summer. Now, the longtime teacher is preparing to start radiation treatments, and James says the kids’ surprise was just the boost she needed before going into the difficult process.

“I was already feeling relieved that my last chemo was over, but I also knew how I was going to feel in the coming days,” she tells PEOPLE. “So that was a very nice way to go into that time where I knew I was going to feel awful and sick. To start it with such a positive, loving gesture was really special.”

James’ longtime friend, Brigitte Welty, organized the special moment, working with James’ husband, Jeff James, and her two children, Jared, 20, and 17-year-old Carly. That morning, the students and parents held their signs, waved, and rang the bells excitedly as James arrived home.

One mother, Ivana Firestone, says James’ reaction was priceless.

“She was so moved by the whole thing. It’s just a little thing that could really make someone’s day,” Firestone, who says James previously taught her son at the school, tells PEOPLE.

“There were maybe 15, 20 students. I don’t think there was a dry eye in the house. It was very emotional. For the kids, just to see that [James is] doing alright was a really big thing.”

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Just after the event, Firestone says that James couldn’t help but share her excitement about the surprise in a sweet text message.

James wrote: “I am so full of love and gratitude right now. I can’t stop smiling. That was amazing!!! The effort and time, the signs, flowers, cards and bells … not to mention the sweet smiling faces of the kids. Oh my gosh I miss them all so much. It overwhelms me. Thank you so much for helping it happen and for being there. I hate that the chemo flu is on its way, but so glad it’s the last one. Xo.”

James has not been able to teach since the end of the 2017-2018 school year, but she says she can’t wait to head back to school.

“I’m very excited to get back into the classroom. This is a wonderful group of children and I know that they’re eagerly waiting for that,” she tells PEOPLE. “I know that it will bring me a lot of joy. The joy of children is very healing.”