All 3 CMs combined:
(CM#1 "from father to son"; CM#2 "from mother to daughter"; CM#3 "from daughter to father")
Uploaded by Aiueotanasinn06
Official website: http://walkwithyou.jp/?page=cm_hakone1
The young actor in the cm is Sometani Shota who's gained much attention from the movie Himizu. He looked so shy and cute at the part when Maki was looking at him. You'll also notice the older actor as Maki's co-star in "Umareru" where he played the doctor.
Special thanks to the uploader Aiueotanasinn! Arigatou!