About letting high-school students have cellular phones 高校生に携帯電話を持たせることについて
As my thoughts on, it is essential for high-school students to use smart-phone.
This is just because Japan is homogeneous community.
As long as you are in this society, it is vital to have conformity and obey the pressure to comform.
Unless you give your children cellular phone, he or she will be bullied.