Spring roll is popular food in Japan but spring roll in Japan is not the Vietnamese style which use the rice paper but uses the wheat pastry as like the Chinese one.
Vietnamese style spring rolls can be ordered at Vietnamese restaurants only but you can find this Chinese style not only at Chinese restaurants but also at diners too. However, it is hard to find at ramen noodle bars where usually offer different dim sum; gyoza - fried dumplings.
Then, spring rolls are dipped to soy sauce, rice vinegar, and chili oil but it is also popular to eat with a Japanese mustard too.