\documentclass[]{standalone}
\usepackage[]{graphicx}
\usepackage[]{luatexja-preset}
\usepackage{tikz}
\usepackage{pgfplots}
\pgfplotsset{compat=1.17}
\tikzset{>=latex}
\usetikzlibrary{arrows,arrows.meta}
\usepackage{steinmetz}
\newcommand*{\equal}{=}
\usepackage{tikz-3dplot}
\usepackage[european resistors]{circuitikz}
\usetikzlibrary{decorations.markings}
\tikzset{->-/.style={decoration={
markings,
mark=at position #1 with {\arrow{>}}},postaction={decorate}}}
\tikzset{-<-/.style={decoration={
markings,
mark=at position #1 with {\arrow{<}}},postaction={decorate}}}
\begin{document}
\begin{tikzpicture}
\begin{axis}[
unit vector ratio*=1 1 1,
width=0.8\textwidth,
%axis y line=middle, axis x line=middle,
hide axis,
scale only axis,
ticks=none,
xmin = -1, xmax = 4.5,
ymin = -1, ymax = 4.5,
xlabel={$\mathrm{Re}$},
ylabel={$\mathrm{Im}$},
]
\draw[->] (5,0) -- (-0.8,0) node[below] {$\mathrm{Im}$};
\draw[->] (-0.5,-0.5) -- (-0.5,2.5) node[left] {$\mathrm{Re}$};
\draw[] (-0.5,0) node[below=5pt,right=-3pt]{O};
\draw[] (4.4, 0.2) -- (0.4, 0.2);
\draw[] (4.4, 0.2) arc(0:180:2);
\draw[] (-0.5,0.2) node[circle, fill,inner sep=0pt, minimum size=3pt]{} node[left]{$\mathrm{N'}$} -- (0.4,0.2) node[circle, fill,inner sep=0pt, minimum size=3pt]{} node[below]{N};
\draw[] (-0.5,1.93) node[circle, fill,inner sep=0pt, minimum size=3pt]{} node[left]{$\mathrm{S'}$} -- (3.4,1.93) node[circle, fill,inner sep=0pt, minimum size=3pt]{} node[above]{S} -- (3.4,0.2) node[circle, fill,inner sep=0pt, minimum size=3pt]{} node[above=5pt,right]{U};
\draw[] (0.4,0.2) -- (3.4,1.93) node[circle, fill,inner sep=0pt, minimum size=3pt]{} node[above=5pt,right]{};
\draw[] (1.38,2.07) -- (2.4,0.2) node[circle, fill, inner sep=0pt, minimum size=3pt]{} node[below]{C} -- (2.01,2.3);
\draw[] (0.4, 0.2) -- (3.4,0.7) node[circle, fill,inner sep=0pt, minimum size=3pt]{} node[right]{T};
\draw[] (0.4,0.2) -- (0.03 ,0) node[circle, fill,inner sep=0pt, minimum size=3pt]{} node[below]{D} -- (0.03,1.93) node[circle, fill,inner sep=0pt, minimum size=3pt]{} node[left=5pt,above]{F} -- (0.03, 2.0);
% %直角マーク
\draw[] (2.35,0.47)--(2.4,0.477) -- (2.393,0.53); %
\draw[] (1.87,1.05)--(1.845,1.093) -- (1.9,1.13); %
\draw[] (1.445,1.96) node[circle, fill,inner sep=0pt, minimum size=3pt]{} node[above=2pt,inner sep=0pt,fill=white,opacity=0.9]{$\mathrm{P_m}$} -- (1.445,0.8) node[circle, fill,inner sep=0pt, minimum size=3pt]{} node[below]{$\mathrm{Q_m}$};
\draw[] (2.03,2.17) node[circle, fill,inner sep=0pt, minimum size=3pt]{} node[left=2pt,above]{$\mathrm{P_t}$} -- (2.06,0.483) node[circle, fill,inner sep=0pt, minimum size=3pt]{} node[below]{$\mathrm{Q_t}$};
\draw[] (0.4,0.2) -- (0.4,1.43) node[circle, fill,inner sep=0pt, minimum size=3pt]{} node[left]{G}-- (3.4,1.93);
\draw[] (0.03,1) node[circle, fill,inner sep=0pt, minimum size=3pt]{} node[left]{H} -- (0.77,1.359) node[circle, fill,inner sep=0pt, minimum size=3pt]{} node[right=7pt,below=-3pt]{$\mathrm{P_n}$} -- (0.77,0.27) node[circle, fill,inner sep=0pt, minimum size=3pt]{} node[below=7pt,right=-5pt]{$\mathrm{Q_n}$};
\draw[] (-0.5,1.359) node[circle, fill,inner sep=0pt, minimum size=3pt]{} node[left]{$\mathrm{P'_n}$} --(0.77,1.359);
%fill=white,inner sep=1pt, opacity=.9
\draw[] (0.77,1.359) -- (-0.5,0);
\draw[] (0.77,1.359) -- (0.03,0) -- (1.3,2.332) node[above]{\tiny{$\mathrm{DP}_n$の延長}};
\draw[] (0.4,0.2) -- (0.77,1.359) -- (0.85, 1.609) node[above=3pt, inner sep=0pt,fill=white, opacity=0.7]{\tiny{$\mathrm{NP}_n$の延長}};
\draw[] (1.08,1.93) node[circle, fill,inner sep=0pt, minimum size=3pt]{} node[above]{$\mathrm{Y}$};
\draw[] (0.81,1.50) node[circle, fill,inner sep=0pt, minimum size=3pt]{} node[inner sep=0pt,fill=white, opacity=0.8,left=3pt]{$\mathrm{R}$};
\end{axis}
\end{tikzpicture}
\end{document}
