Waku Waku! Pop'n Manga (partially found online Japanese 4-koma manga; 2006-2012)
Waku Waku! Pop'n Manga (わくわく! ポップンマンガ) was a Japanese 4-Koma manga that was published weekly via the paid mobile site, KonamiNet DX. It was based on the Japanese rhythm game, Pop'n Music, a rather successful game from Konami's own BEMANI line of rhythm games. It ran from August 25th, 2006, to March 23rd, 2012, with a total of 934 episodes published.
On August 25th, 2006, publication first began for the manga on KonamiNet DX, a Japanese paid mobile site accessible via the i-mode, EZweb, and Yahoo! Keitai mobile services. The strips were also published via other paid mobile sites, Weekly Konami (formerly Digital Comics), and Weekly Konami Petit. KonamiNet DX was where the strips were first published, but Weekly Konami had back issues of comics, in case you missed them on KonamiNet.
The manga saw a renewal on July 6th, 2007, when it became a full-color manga with sound effects. Also, instead of 2 strips per week, there were now 4 strips coming out each week.
After November 6th, 2009, those using i-mode and Yahoo! Keitai had to register for Weekly Konami to read new strips. In addition, if a person wanted to read past issues of the strips from KonamiNet DX or Weekly Konami Petit, they would have to use points. (which were likely obtained via real-life currency) However, if the person was using EZweb, the person could continue to browse past issues of the manga without using points.
After October 27th, 2011, Weekly Konami Petit was no longer in service. Instead of this app, people could have viewed the latest strips in image-only format via the Comic Corner on KonamiNet DX. Distribution of the issues via Weekly Konami continued.
On March 31st, 2012, Weekly Konami ended its service, with 934 Pop'n Manga strips published in total. However, a person could still view a majority of the strips via KonamiNet DX. All of these strips were available right up until KonamiNet DX finally ended its service on April 30th, 2016.
Since the comics were only available via a paywall, almost all of the strips were completely lost after KonamiNet DX closed its doors. It is unlikely that anyone posted them externally, since doing so would have been illegal. There is a possibility that some people may have stored the strips on their phone's memory, but finding these saved copies would be near-impossible. It is likely that Konami has an internal archive of all these strips, but finding these would again, be near-impossible.
Pop'n Music Magazine
On December 12th, 2008, Konami Style announced there would be a limited-supply publication of Pop'n Music Magazine, a Pop'n Music-related magazine that people could purchase from Konami starting December 24th. There were 5 issues made of the magazine, from December 24th, 2008, until April 24th, 2009. The first four issues could be ordered via a first-come, first-serve basis, whereas the 5th issue, a special 32-page edition, could only be purchased via Konami Points.
Inside every issue of the magazine, there were a select few strips from Waku Waku! Pop'n Manga included. A few of these strips have been posted online from various people on the internet. This is the only known physical publication of these comics.