My son will be traveling to Tokyo in September for a study abroad program. The program representatives will be meeting people at Narita but, because we used Delta miles for his ticket, he has to fly to Haneda and get to his first destination from there. The hotel where he will be spending his first few nights is in Shinjuku. I am thinking the easiest way for him to get there is to spring for a car service and I'm wondering whether anyone has used one recently. Thanks!

There is an airport limo bus from Haneda to Shinjuku that takes maybe 45 minutes
and costs less than $10. I think the buses run a few times an hour depending on the time of day. Taxi would cost about $50-60.

Last time in Tokyo we arrived at Haneda and were staying in Shinjuku. We just got the train which was pretty straightforward.

If your son’s hotel is near a limo bus stop it will be the easiest transfer, especially if he has significant luggage as he will be in Japan for several months. When I moved to the Uk to study I just had a back pack and medium size luggage. When I moved my daughter to Uni in London we bought with us about 6 X more luggage. . I think the younger generation tends to have more stuff. There are multiple other ways to get to Shinjuku. Monorail to Hamamatsucho than JR Yamamote line. Taking the Keikyu train to Shinagawa than onto the JR Yamanote line is faster. Haneda is a nicer airport than Narita and in the city so much closer than Narita which is about 2 hours outside the city.

Which hotel?

I would take a limo bus. I have not used a car service. Haneda transfer waa a recent topic on flyertalk. Based on that, and my impression of the company, if I were to use a car service it would be: Airport Transfer | Tokyo MK

Thanks so much for these comments. He is trying to keep luggage reasonable but he's going for a year so he will have a backpage and a larger suitcase - so we are trying to avoid options that would require him to change trains. The hotel is Hotel Sotetsu Grand Fresa.

Has he considered luggage forwarding, aka "takuhaibin." Reliable and surprisingly affordable.
https://www.japan-guide.com/e/e2278.html

I think you mean Sotetsu Grand Fresa Takadanobaba
Tokyo Haneda Airport (HND) to SOTETSU GRAND FRESA TAKADANOBABA, Tokyo (rome2rio.com)