It’s hard to pick just one thing to get excited about at Ewa Makai Middle School, Hawaii’s newest, most energy-efficient and state-of-the-art public school campus.

But on the first day of classes yesterday at Ewa Makai, where some 600 students spent the morning taking guided tours with teachers, Tamara Tsuha gave it a stab.

"It has AC!" the 13-year-old said, practically bouncing in her seat. "And it’s all new."

There are other things, too, that appeal to Tsuha: classrooms equipped with interactive "smart" boards and flat-panel televisions; "roving" iPad and laptop labs; and a host of eco-friendly features, such as overhead lights that turn off when no one is in the room and a large, sunny courtyard bordered by native plants.

Ewa Makai was built, at a cost of $67 million, to relieve serious overcrowding at Ilima Intermediate, where the student body topped 1,400 before seventh- and eighth-graders bound for the new campus made the switch yesterday. Construction of the 18.5-acre campus began in July 2009 and was concluded last month.

And though the campus officially opened yesterday, there is still work to do. The school library, for example, does not yet have any books. Those will come in starting next month. In the meantime, students have access to online collections. (The library, even with books, will rely heavily on electronic resources.)

Principal Ed Oshiro said it has been quite an undertaking to open the new campus. He has spent the last year hiring staff, buying materials and ironing out last-minute details. Oshiro and his office workers were at the school until 10:30 Monday night wrapping up a host of little jobs, like making ID badges.

But Oshiro was all smiles yesterday morning as he greeted students and faculty, welcoming them to the new campus and pledging to help make Ewa Makai the best school in the state — and not just because of its gold-standard facilities.

"We want it to be an exceptional school," he told reporters.

For Oshiro, opening Ewa Makai is the fulfillment of a lifelong dream.

Oshiro was contemplating retirement when he heard about the Ewa Makai opening. He jumped at the chance and said though it has meant lots of work, he has loved every minute of it. "I’m just ecstatic," he said yesterday before posing for his ID badge photo with the school’s mascot, a plush toy tiger.

Department of Education officials say Ewa Makai’s state-of-the-art facilities provide a model for future school campuses. The school is the first in Hawaii to be built under one roof for energy efficiency and to increase collaboration among students, and meets federal "silver" energy-efficiency ratings.

It also has innovative spaces, like a dance studio and a robotics workshop.

"It feels like every kid wants to go to this school," said Jessica Samante, an eighth-grader at Ewa Makai. Her favorite feature is the outside courtyard, where students can gather during breaks and lunch. "Who doesn’t love this school?" she asked.

Correction: Ewa Makai Middle School cost about $67 million to build. An earlier version of this story had an incorrect amount. Construction also began in july 2009, not in July 2008 as originally reported.