The greatest difference between western and eastern calligraphy when considering a tattoo is the meaning: In western we have precise words or phrases and the way of writing them can vary. In eastern, the amount of words is quintupled or unquantifiable in some cases (japanese and chinese, respectively). Because of that, a simple google or AI translation can sometimes give way to meanings that weren't the original idea. Our solution? Consult an expert or a native, both if possible.
Since social networks have become a thing, we're more exposed to the eyes of others and, for good or bad, subject to judgement or appraisal. It's better then to properly relay the concept or meaning that we had in mind. Japanese calligraphy in particular is great for this, because entire phrases or concepts can be condensed or explained with a single stroke of a brush, but the beauty of it is that it isn't limited to one particular kanji: There's almost always another one that can explain differently or give specifics to each concept. Our resident artist Horisen excels at finding and expressing such concepts, one of which is Isshindoutai: Two or more persons joined by the heart and who are as close to each other as one single person