gistfile11

" For test (Do quickrun on the target character!):
" aiu
" あいう

function! s:get_current_character()
    if mode() ==# 'c'
        let str = getcmdline()
        let cur_idx = getcmdpos() - 1
        return matchstr(str, '.', cur_idx)
    elseif mode() ==# 'n'
        let str = getline('.')
        let cur_idx = col('.') - 1
        return matchstr(str, '.', cur_idx)
    else
        echoerr 'not supported'
    endif
    return char
endfunction

echom s:get_current_character()