I've fixed C#'s I/O by making it as Bjarne Stroustrup intended.

StroustrupWouldBeProud.cs

using static System.Console;

namespace NoticeMeSenpai;

public class Program {
	const string endl = "\n";

	public static int Main() {
		S a = "Hello", b = "World!";
		C cout, cin, _;
		_= cout < a < " " < b < endl;
		_= cin > a > b;
		_= cout < "a: " < a < endl;
		_= cout < "b: " < b < endl;
		return 0;
	}

	public struct C {
		public static C operator <(C _0, S _1) { Write(_1); return _0; }
		public static C operator >(C _0, S _1) { _1.s = ReadLine(); return _0; }
	}
	public class S {
		public string s;
		public S(string s) => this.s = s;
		public static S operator <(S _0, S _1) => _0 + _1;
		public static S operator >(S _0, S _1) => _0 + _1;

		public static implicit operator string(S _0) => _0.s;
		public static implicit operator S(string _0) => new(_0);
	}
}