Mason and Sean Kobold won't be the first people to graduate at the Corn Palace, but their graduation Saturday will mark a different kind of first.

When the twins walk across the Corn Palace stage with Mitchell High School's graduating class, they will become the first people enrolled at Mitchell's Behavior Care Specialists location, which offers behavioral treatment to those on the autism spectrum, to have graduated.

"This is the biggest milestone. They started out in the NICU in Sioux Falls," said Shanna Kobold, Sean and Mason's mother. "I didn't think we were going to get this far."

Both Mason and Sean Kobold told The Daily Republic on Tuesday that they're excited for graduation, an experience they'll share with people they've known since they were students at Gertie Belle Rogers Elementary School together.

Demetrius Wells, who has worked closely with the Kobolds at BCS, said the twins' graduation will be bittersweet.

"It's an amazing experience watching them grow. It's phenomenal, from the time I've gotten here until now, to see (them) mature. I can't tell you how many stories I have about them," Wells said. "It's like watching your own kid go across the stage, and it's tough, at the same time, that they have to move on. They're not little kids anymore. They're becoming young men. It's also very beautiful."

Mitchell's is one of 17 BCS locations across four states, and the twins were the reason the organization came to town. When the Kobolds were in seventh grade, they became BCS' first clients in Mitchell.

"Since (BCS has) been here, they've been able to expand out and help other kids, so it's been a blessing," Shanna Kobold said.

The branch now has 14 students and balances classwork with other activities - for instance, the Kobolds said they're excited to visit water parks over the summer.

"We try to make things fun for them," Wells said. "Obviously, we're going to do what we think is reinforcing for them. There's also a lot of work involved."

Currently, Mason starts his weekdays at Mitchell High School before heading to BCS. Sean, who Shanna Kobold said tends to prefer smaller group settings, goes to the high school for a class every other day.

At BCS, Wells said he would describe the two brothers as "legends," in part because of the attitudes they bring to affect others positively.

"We like to make everybody have fun," Mason said.

After graduation, Mason and Sean will continue going to BCS through the summer, which Shanna Kobold said is intended to keep things in balance for them. They're planning to transition to LifeQuest, where Mason is considering joining the workforce program.

"They are capable of phenomenal things if they put their minds to it," Wells said. "All I can say for these gentlemen is just, job well done. ... I've learned a lot working with them and working for them. I've learned a lot about myself."