Japanese sentiment toward Russia is quite subtle

Russia is close to our country, but because of the division, we do not share a border, so the perception of them being a neighboring country is somewhat faint. Naturally, there isn't much thought regarding them in terms of public sentiment.
On the other hand, because the Japanese are separated by the sea, they are much more sensitive to their relationship with Russia. Furthermore, as the closest victorious nation of World War II, they also have trauma regarding the war.
Judging that they had gained the trust of the United States after the war, Japan abolished its anti-communist policy and established diplomatic relations with the Soviet Union in 1956. This was a necessary measure for Japan in terms of security and maritime expansion.
However, they still view Russia as a dangerous country. In fact, they are more wary of modern Russia—a hardline nationalist state and rival—than the Soviet Union, which had advocated for ethnic equality.

Above all, the islands east of Hokkaido that were ceded to Russia during the war are the biggest point of anger for the Japanese people. Not long ago, around Liberation Day, there was an uproar across Japan when Putin visited those islands. Unlike Dokdo, which is a distant island, these islands are close to the mainland, so the level of interest among the Japanese is high.
Russia claims, "It is territory transferred to Russia along with Sakhalin," while the Japanese side argues, "Since those islands were under the jurisdiction of Hokkaido and not Sakhalin in terms of administrative districts, they are not subject to cession."