Let the sun shine into your ear while sitting on a stool and make sure most of it gets in your head. You want to fill your brain with the most sun anyone has ever.
Most of this is for your cyborg (さい). You're testing out a new way to power it, but if you can't get most of the sun into your ear, it won't be enough to power most of the cyborg's robo-parts.
Currently there are no similar looking kanji which exist in the WaniKani learning system