Mojibake is happening on the uploader, as you can see from https://world2ch.net/uploader/src/216.lua
The provided alternates should look a little like:

--[[
-- Alternate names and units. Japanese shakkanhou chou, and Japanese kanji names provided.
["unit"] = {
	["name"] = "町",				-- Display name
	["conversion"] = 11/1200,	-- Meters * This -> Unit
	["precision"] = 1,			-- Decimal
},
["name"] = {
	["Sapporo"] = "札幌 (Sapporo)",
	["Hakodate"] = "函館 (Hakodate)",
	["Fukushima"] = "福島 (Fukushima)",
	["Oi"] = "大井 (Oi)",
	["Kokura"] = "小倉 (Kokura)",
	["Hanshin"] = "阪神 (Hanshin)",
	["Kyoto"] = "京都 (Kyoto)",
	["Chukyo"] = "中京 (Chukyo)",
	["Nakayama"] = "中山 (Nakayama)",
	["Tokyo"] = "東京 (Tokyo)",
	["Niigata"] = "新潟 (Niigata)",
},]]

If the script is producing an HTML page to serve text files, you should probably add <meta charset="UTF-8"> to the page.