Dinosaur Jr.’s 1994 song “Over Your Shoulder” hit the Billboard Japan charts this week, topping the Hot Overseas chart and entering the Hot 100 at #18 (above other Western artists such as Ariana Grande and Queen). The closing track from their album Without a Sound garnered the majority of its plays in Japan via YouTube, according to a Billboard report, racking up a staggering 8 million views last week.

“Over Your Shoulder” was never released as a single, and has not been reissued in any capacity in Japan recently. It does not appear in a new popular film, nor does it appear to soundtrack a meme or viral video. Pitchfork has been unable to source the video or videos that garnered these plays; Billboard was also unable to find the source of the 8 million views. “The likely answer is that some unknown user uploaded a video or videos using these songs, which were then viewed enough times for the songs to make significant inroads into the ranking,” their report reads. It is possible that the videos in question are region-locked to Japan.

One possible explanation: Some Japanese readers have claimed that the song was once used in a popular TV show called “Gachinko Fight Club,” which originally aired from 1999-2003. According to Dinosaur Jr. representatives, old episodes of “Gachinko Fight Club” featuring “Over Your Shoulder” were uploaded to YouTube, linking the credits and registering the copyright of the song. Nostalgia for the series was sparked by the appearance of one of the cast members on a more recent show, “Tokio Kakeru,” spurring people to seek out the old “Gachinko” episodes.

Update (02/12 12:41 p.m. Eastern): Billboard has issued the following statement to Pitchfork:

The Japan Hot 100 incorporates YouTube views within Japan of audio and video assigned with an ISRC code. This includes user-generated clips that utilize authorized audio. We believe a recurring segment from an old terrestrial TV variety program—which prominently featured Dinosaur Jr.'s "Over Your Shoulder" as well as the non-Japanese tracks that mysteriously appeared on the Japan Hot 100 dated Feb. 11 [tracking date: Jan. 28 to Feb. 3]—went viral due to renewed interest, resulting in users to binge watch YouTube videos of the segment using these songs, racking up significant views to impact the chart. Some of these user generated clips were then deleted, however new videos keep being re-uploaded which may result in these songs to appear again on this week’s Japan Hot 100, to be posted on Feb. 13.

This article was originally published on Friday, February 8 at 2:31 p.m. Eastern. It was last updated on February 9 at 1:35 p.m. Eastern.