Apple Inc.’s iPhone 6s and iPhone 6s Plus smartphones went on sale in Japan on Friday, pitting the country’s three major mobile phone carriers against each other in a fierce competition to win new subscribers.

The new models feature 3-D Touch technology that recognizes how hard users touch screens, enhanced cameras, and 4K video recording. They come in four colors, including “rose gold,” a new addition.

At Apple’s retail store in Tokyo’s Shibuya Ward, around 40 people lined up to get new iPhones, while NTT Docomo Inc., KDDI Corp. and SoftBank Corp. held events to celebrate the launch, which is also taking place in other markets around the world Friday.

“I can’t wait to try out shooting videos in 4K, among other things,” said 30-year-old Tokyo company employee Sho Hashiguchi, an avid fan of the iPhone series who purchased the high resolution technology.

The latest models, following last year’s hugely popular design overhaul that featured enlarged screens, may not match the success of previous releases, according to analysts.

Demand for the new iPhones appears to be lower than last year, “possibly meaningfully so,” said Andy Hargreaves, an analyst at Pacific Crest Securities who studied Google search data, device shipment times and third-party surveys. Analysts at Sanford C. Bernstein & Co. and RBC Capital Markets also raised concerns about iPhone growth.

Since 2013, iPhone sales have increased an average of about 35 percent each quarter. In October to December alone last year, Apple sold 74.6 million iPhones. That’s about 34,000 purchases per hour.

Expectations are tempered partially because the gadget is at the point in its two-year design cycle that includes less dramatic changes. In the first year, Apple generally overhauls the device’s hardware, including its look and feel. For the following year’s model, designated with an “s” tacked onto the number, the Cupertino, California-based company makes more subtle improvements.

The iPhone 6s and 6s Plus look like last year’s versions but include new features such as 3D Touch, which provides a shortcut for checking mail, taking pictures and other functions when the user presses down on the screen. Apple also added a zippier processor.

A smooth release is critical for Apple, which generates more than 60 percent of its revenue from the phone. The company is attempting to expand other businesses, but the portion of sales coming from the iPhone continues to grow. The Apple Watch hasn’t become a mainstream hit since it was released earlier this year and iPad sales are in decline.

The three mobile phone operators in Japan have announced their own price plans for the iPhone 6s and 6s Plus, setting minimum amounts that subscribers need to pay at over ¥10,000 ($84) based on two-year contracts.

NTT Docomo is offering the cheapest plan of the three for people switching from its rivals, charging ¥432 a month, or ¥10,368 over two years for the iPhone 6s. For the iPhone 6s Plus, subscribers will need to pay ¥972 a month, or ¥23,328 over two years.

When the iPhone 6 and 6 Plus debuted last year, Apple sold 10 million units in the three days after launch.