bus from Kanoya to Nejime? (Kagoshima pref)

I'm researching a route from Nichinan (Miyazaki pref) to Ibusuki, first via train to the Shibushi terminus, then bus to Kanoya, and another bus to Nejime port (ͺθ`) for the Nankyu ferry to Yamakawa near Ibusuki. This would be on a sunday. I found this schedule for the bus to Nejime: http://www.e-kanoya.net/htmbox/kikaku/bus/daiya/07_v2.pdf
My japanese is limited and I'm not sure which buses run on sunday and which don't. Does only the "black triangle" at 8:20 run, or also the unmarked ones? Are there perhaps other bus companies/lines to get from Shibushi to Nejime? If there's no bus getting me there in time for the 14:30 ferry, I guess I'll have to scrap this route. Thanks in advance for any info : )

White triangle: doesn't run on Sundays and holidays
Black triangle: runs only on Sundays and holidays
The other ones run every day.
Hope this helps :)

I know the region and I have three times crossed from/to Nejime/Yamagawa, but always in car.

So, I tried from curiosity to find the proper buses and connexions, on the
condition of non week day time table, id. on Sundays and national holidays. Unfortunately, there seems to be no direct bus from Shibushi to Nejime port.

Train from JR Nichinan station to JR Shibushi station
Departures: 07:19 (next train 11:51)
Arrivals : 08:37 ( 13:10)

Bus from Shibushi-eki-ue to Kanoya
Departures from Kanoya-eki-ue: 08:47/09:27/10:30/11:37/12:45
Arrivals at Kanoya: 09:50/10:25/11:30/12:35/13:45
(See Shibushi station location map of Bus stops)
http://www.city.shibushi.lg.jp/docs/2013101000242/files/download2.pdf

Bus from Kanoya to Nejime or Nejime Port
Departures: Kanoya City Hall 13:54/15:19
Arrivals at Nejime Port 14:37/16:03
This part of the route is the very problem. There are only two buses going to Nejime Port. Some convenient buses donft run on Sundays and holidays.

Departures from Nejime port to Yamagawa port are:
(Until October 31) (From November to February)
9:00 9:00
11:00 11:00
13:00 13:00
14:00 14:30
15:00 16:30
17:00

In conclusion, I am sorry, but your plan seems to be impossible unless you accept the ferry of 15:00 or 16:30, or unless you use a taxi or hitchhike from Kanoya to Nejime or from Shibushi directly to Nejime.

(The crossing takes about 50 minutes.
The ferry boat crossing gives you a splendid view, I assure you.)

Thanks! Indeed that second bus is timed very inconveniently. I guess this time I'll take the northern/land route instead, also a nice option with some scenic trains. I'll leave the Nankyu ferry route for next time, on a weekday : )