Ichiro Yamaguchi

According to this post, his guitar is a 1973 Gibson ES-335.

In the YouTube video titled "忘れられないの from NF OFFLINE," Ichiro Yamaguchi is seen using the Gibson '60s J-45 Original while performing an acoustic version of Wasurerarenaino. The video was posted by the official サカナクション sakanaction Youtube channel.

In the YouTube video titled "サカナクション / プラトー -Music Live Video-" by サカナクション sakanaction, Ichiro Yamaguchi is seen playing a Fender Traditional 60s Jaguar at the 3:25 mark. It is likely a Made-in-Japan model, as indicated by the headstock, which is painted to match the body color.

Ichiro Yamaguchi is seen using a black Rickenbacker 425 guitar at the 0:30 mark of the video titled "サカナクション / ワンダーランド from 『SAKANAQUARIUM 光 ONLINE』," which is provided by サカナクション sakanaction on YouTube.

Ichiro Yamaguchi's Korg KAOSS Pad 3 can be seen at the 1:37 mark of the video titled "サカナクション LIVE Blu-ray/DVD『SAKANAQUARIUM 2024”turn“』-Digest Movie-" published by the サカナクション sakanaction official Youtube channel.

In this YouTube short he's playing a Monaco Yellow Telecaster on the song aoi

Ichiro Yamaguchi uses a Rickenbacker 330 Electric Guitar, as confirmed by a photo he shared on Instagram with the caption: "リハ。Rickenbacker330。青春時代、治験のアルバイトをして買った大事なギター." Additionally, he can be seen playing this guitar in Sakanaction's music video for "Takarajima."