Usui in Chinese / Japanese...

These are the precepts of Reiki that are attributed to Usui Mikao.

Here is a breakdown of the characters and a rough translation:
招福の秘法,　萬病の霊薬。
Invite blessings of [the] secret method, 10,000 illnesses of spiritual medicine.
今日丈けは:　怒るな,　心配すな,　感謝して,　業をはげめ,　人に親切に。
At least for today: Do not be angry, do not worry, be grateful, work with diligence, and be kind to people.
朝夕合掌して,　心に念じ,　口に唱へよ,　心身改善。
Morning [and] evening perform gassho (join hands), [with your] heart/mind in silent prayer, [with your] mouth chant, [thusly] mind [and] body [will] reform/improve.
臼井靈氣療法！　-肇祖,　臼井甕男。
Usui Reiki Ryōhō! -Founder, Usui Mikao.

The middle portion of this is often titled, “The Five Principles of Reiki” and makes a nice calligraphy selection by itself. The Japanese text presented here can be considered the more verbose version.

Note: Because this selection contains some special Japanese Hiragana characters, it should be written by a Japanese calligrapher.

靈氣療法肇祖臼井甕男先生遺訓招福の秘法萬病の霊薬今日丈けは心配すな感謝して業を励げめ人に親切に is an alternate version of the precepts or tenets of Reiki by Usui Mikao.

It is impossible to be sure which version or versions were actually written by Usui Mikao. This is the less common of the three versions that you might see in the wild.

Here is a breakdown of the characters and a rough translation:
靈氣 療法 肇祖 臼井甕男。
Reiki therapy founder Mikao Usui
先生 遺訓。
Teacher's testament 招福の秘法,　萬病の霊薬。
Invite blessings of [the] secret method, 10,000 illnesses of spiritual medicine.
今日丈けは: 怒るな, 心配すな,　感謝して,　業をはげめ,　人に親切に。
At least for today: Do not be angry, do not worry, be grateful, work with diligence, [and] be kind to people.

Note: Because this selection contains some special Japanese Hiragana characters, it should be written by a Japanese calligrapher.