TOKYO — Brandishing a new Sony Xperia as she left a mobile phone shop in a trendy part of Tokyo, Nisako Hanawa, a 17-year-old student, explained that she had chosen that brand “because of its cool design and its good reputation.”

Asked about another leading smartphone maker, Samsung Electronics of South Korea, she and a friend exchanged quizzical looks. “Samsung?” Miss Hanawa asked. “I haven’t heard of it.”

Samsung Electronics may be the largest consumer electronics company in the world, selling one out of every three smartphones and one in five televisions. LG, the other giant electronics maker in Korea, has a significant share of TV and washing machine markets in Europe and the United States. But here in trend-obsessed Japan, consumers have not caught on that elsewhere in the world some Korean products are knocking Japanese rivals off the shelves.

Many Japanese explain away the absence of Korean brands by claiming the quality is inferior. “South Korean products are still affected by a ‘cheap and nasty’ image, which remains prevalent among Japanese above a certain age,” wrote Hidehiko Mukoyama, an economist at the Japan Research Institute, in a research paper about Japan-South Korea trade relations.