The Japanese word, "KOSHISYOKU" pronounces [k o ʊ ʃ í r j o k ʊ]. 「好試力」は、「こうしりょく」と読みます。
It means the power to try favorite things. 好きなことを試す力という意味です。
I can try that I like, and I may help a lot of you, That wiII be my pleasure. 自分が好きなことを試して、少しでも多くの皆さんの役に立てたらいいな。
In that way, both you and I will surely become happy. そうすれば、自分もみなさんもきっと幸せになれるに違いない。
It is a coined word with such wishes. そういう願いを込めた造語です。

By the way, do you know Super Robot animation "Mazinger Z", ところで、日本で1972年12月3日からテレビ放送された、
that is authored by Go Nagai, that was broadcasted from December 3, 1972 in Japan? 永井豪先生原作のスーパーロボットアニメ『マジンガーZ』をご存知ですか。
The power source of Mazinger Z is "Photon Power".
It has same pronounciation of "KOSHISYOKU" in Japanese. マジンガーZの動力源は「光子力」、
The building that comes out in that story is "Photon Power Laboratory", "KOSHISYOKU Laboratory" in Japanese. その物語の舞台は光子力研究所です。

This English version is a reference translation. A formal version is assumed to be a Japanese version.