var oldstring = argument0;
var newchar = argument1;
var len = strlen(oldstring);
if (!(newchar >= "a" && newchar <= "z"))
{
    if (oldstring != "" && string_char_at(oldstring, len) == "n")
        oldstring = substr(oldstring, 1, len - 1) + "ん";
    if (newchar == "-")
        newchar = "ー";
    if (newchar == "/")
        newchar = "・";
    if (newchar == "[")
        newchar = "「";
    if (newchar == "]")
        newchar = "」";
    return oldstring + newchar;
}
if (oldstring == "")
    return newchar;
var lastchar = string_char_at(oldstring, len);
if (!(lastchar >= "a" && lastchar <= "z"))
{
    if (newchar == "a")
        newchar = "あ";
    if (newchar == "i")
        newchar = "い";
    if (newchar == "u")
        newchar = "う";
    if (newchar == "e")
        newchar = "え";
    if (newchar == "o")
        newchar = "お";
    return oldstring + newchar;
}
if (!(newchar == "a" || newchar == "i" || newchar == "u" || newchar == "e" || newchar == "o"))
{
    if (lastchar == "n")
    {
        oldstring = substr(oldstring, 1, len - 1) + "ん";
        lastchar = "ん";
    }
    else if (newchar == lastchar)
    {
        oldstring = substr(oldstring, 1, len - 1) + "っ";
        lastchar = "っ";
    }
}
if (len >= 3)
{
    var compose4 = ds_map_find_value(global.kanatype_lookup_4ch, substr(oldstring, len - 3) + newchar);
    if (!is_undefined(compose4))
        return substr(oldstring, 1, len - 3) + compose4;
}
if (len >= 2)
{
    var compose3 = ds_map_find_value(global.kanatype_lookup_3ch, substr(oldstring, len - 1) + newchar);
    if (!is_undefined(compose3))
        return substr(oldstring, 1, len - 2) + compose3;
}
var compose2 = ds_map_find_value(global.kanatype_lookup_2ch, lastchar + newchar);
if (!is_undefined(compose2))
    return substr(oldstring, 1, len - 1) + compose2;
if (newchar == "a")
    newchar = "あ";
if (newchar == "i")
    newchar = "い";
if (newchar == "u")
    newchar = "う";
if (newchar == "e")
    newchar = "え";
if (newchar == "o")
    newchar = "お";
return oldstring + newchar;