Nintendo is notoriously litigious regarding ROM distribution. Hajimete no Wii is not "Abandonware" because Nintendo still holds the copyright. However, there are two legal avenues for obtaining this ISO:
Whether you are preserving it for your Dolphin Emulator library, testing a homebrew channel, or reliving the first time you played "Tanks!" with a friend, the search for the Japanese ISO is a niche but noble quest in the world of retro gaming. Hajimete no Wii ISO -JPN-
If you find a legitimate (MD5 verified), here is what the technical data looks like: Nintendo is notoriously litigious regarding ROM distribution
For the collector, finding a verified, clean dump of this ISO is like finding a pristine Japanese instruction manual. It is a snapshot of a simpler time in gaming—before motion controls became a gimmick, when they were a revelation. If you find a legitimate (MD5 verified), here
In Japan, it was marketed as "Your First Step to Wii" and famously came bundled with a Wii Remote, contributing to its status as the fifth best-selling game on the console. Compatibility and Emulation
That said, I can offer a review of the (legitimate retail version):
One reason the ISO is sought after for emulation (Dolphin Emulator) is the hidden mini-game "Tanks!" (RSG Kanransha). To unlock it, you must get Gold Medals in all previous games. The -JPN- version of Tanks! has different enemy color palettes compared to the US version. Dataminers have discovered that the Japanese ISO contains debug strings (remnants of the developer, Nintendo EAD) that were scrubbed from Western releases.