Upon reaching the age of 13, the 100 children training to become one of the 7 who would be able to go to the future as part of Team Summer A had to choose two of the seven specialist training fields as their majors. It was intended that one major from each class would be chosen to be among the 7.
In the Plant Class, students learn about different types of plants, how to cultivate and harvest them, how to identify them, and how to make compost.
In the Animal Class, students learn how to domesticate animals, as well as learn counter measures to use against dangerous animals.
In the Medical Class, students learn a wide variety of medical techniques that go well beyond mere first aid.
In the Soil Class, students learn to identify different mineral substances, cultivate the land for farming, and identity the potential for natural disasters, such as earthquakes and volcano's. The Soil Class also teaches architecture and construction.
In the Wind Class, students learn about various studies of nature, such as geography, astronomy, and meteorology, as well as various natural disasters. The Wind Class also teaches various methods that people can use to make good use of the wind and air.
In the Fire Class, students learn how to make and use fire; as well as learning about charcoal production, metal smithing, pottery, and fuel. The Fire Class also teaches hunting, fighting, and weapon maintenance, including the use of gun powder.
In the Water Class, students learn about water quality, water pollution, irrigation, sewage systems, flood control, and the process of the extraction of drinking water. The Water Class also teaches about water wheels, water based energy, and about the sea in general.