There are letters on the bright blue rug, children are sitting criss-cross-applesauce and the laminated pictures on the wall have the familiar images typical to a kindergarten classroom.

But a closer look reveals something different: the word "green" is followed by "verde," the classroom door is labeled "puerta" and the wall calendar is turned to "agosto."

And the 13 children in Christina Cena's classroom are being spoken to almost exclusively in Spanish.

Thursday marked the first day of school for the new Cesar Chavez Language Academy, a Spanish-language dual-immersion program launched by Santa Rosa City Schools this year.

"It's just a great opportunity," said Amy Yamauchi of Santa Rosa, who dropped her only son, Nicolai Lopez-Yamauchi, off for his first day of kindergarten Thursday. "I think you should be able to speak as many languages as possible. It opens up your possibilities."

The opening of Cesar Chavez Academy on Thursday marks the second time in two years that Sonoma County's largest school district has launched a dual-immersion language school. The Santa Rosa French-American Charter School opened last year with 243 students and on Thursday had 357 students enrolled in kindergarten through seventh grades.

Thursday marked the first day of school not only for the one transitional kindergarten and three kindergarten classes at the Cesar Chavez Language Academy, but all Santa Rosa City Schools, as well as students in the Mark West and Healdsburg districts.

The largest wave of students heading back to school in Sonoma County hits Wednesday, when 19 districts, including Petaluma, Cotati-Rohnert Park, Roseland, Sebastopol, Sonoma Valley and Cloverdale will send approximately 33,400 students back to class.

"There's a happy buzz by both staff and students," said Santa Rosa Superintendent Socorro Shiels, who visited a handful of schools Thursday.

Teachers and students were "very quickly back to the routine," she said.

But for a brand new school like the language academy, housed on the southeast corner of the Comstock Middle School campus, routine is still being established — and for a very young clientele.

"We are going to walk in a line, following Yareli, to see what it looks like," Cena told her charges Thursday morning before their first walk to the restroom.

Cena spoke almost exclusively in Spanish to a group of students who were about 60 percent native Spanish speakers and 40 percent native English speakers. When going over class rules, she pulled out a brown-haired hand puppet named Lucy.

Lucy spoke to the class in English, while Mrs. Cena spoke to them in Spanish.

"I only address them in Spanish," Cena said. "As far as they know, they can only communicate with me in Spanish."

Switching from Spanish to English defeats the purpose of a full immersion Spanish program in the kindergarten year, because students will tune out the foreign language and wait for instruction in their native tongue, she said.

But Lucy, who helped guide students to their snack cubbies and bathroom breaks, will be gone in two weeks, Cena said. After that, it's all Spanish, all of the time, she said.

The school was established with a capacity for 88 students. Enrollment is currently 66 students.

The language academy, which occupies four rooms on the corner of the Comstock campus which also shares space with the Santa Rosa Charter School, now features a kinder-appropriate playground and a secure fence on the western border.

An interior fence separates a Comstock hallway from the language academy kindergartners and a stretch of red tape marks where the language academy hallway ends and the Santa Rosa Charter School area begins.

"It's awesome," said Comstock Principal Laura Hendrickson about the addition of the language academy students.

"I like that it's an investment from the district and the board in the northwest. It's important for the viability of the northwest," she said.

Comstock has suffered years of declining enrollment but has posted growing numbers since hitting a historic low of 319 students in 2011-12. More than 360 Crusaders were on campus Thursday, Hendrickson said.

The two schools are planning literacy partnerships between middle schoolers and kindergarten students, she said.

School Board members on Wednesday night lauded the efforts of principal Anna Guzman in launching dual immersion program under a tight deadline.

"I'm really excited," board member Jenni Klose said. "I think it's really great that we are doing this not just for the 66 kids there, but for the community."

(Staff Writer Kerry Benefield writes an education blog at extracredit.blogs.pressdemocrat.com. She can be reached at 526-8671, kerry.benefield@pressdemocrat.com or on Twitter @benefield.)